Table of Contents

  • EBT compliant commentary on 16-APS 🌬️ 😤
    • (STED 16-APS)
      • (1. kāyā-(a)nupassī)
      • (2. vedanā-(a)nupassī )
      • (3. cittā-(a)nupassī)
      • (4. dhammā-(a)nupassī)
  • Intro
    • unjustified: body of breath
    • breath is one type of body
      • Simile of the bitter melon
  • Commentary on preliminary steps [0.1] to [0.6]
  • Commentary on first tetrad steps [1] to [4]
    • step 3: entire physical body
      • 400 BCE: Pari-nibbāna of the Buddha
      • 237 BCE, KN Ps, canonical Theravada
      • 1 CE, Vimutti-magga by Arahant Upatissa, early Theravada
      • 409 CE Dhyāna Samādhi Sutra
      • 411 CE Tattvasiddhi-sastra 成實論, treatise on various schools of Abhidhamma
      • 500 CE, Visuddhi-magga, late Theravada Abhidhamma, “body/kāya” redefined as mind
      • 1960 CE, Ajahn Lee (Dhammadaro), Theravada, Ajahn Mun Thai Forest tradition
      • 2012 CE, Bhante Gunaratana, "Meditation on Perception", Theravada lineage from Sri Lanka
      • 2013 CE, Thanissaro Bhikkhu, Theravada, Ajahn Mun Thai Forest tradition
    • step 4: tranquilizing bodily processes
  • Commentary on second tetrad steps [5] to [8]
    • step 8: calming mental fabrication
  • Commentary on third tetrad steps [9] to [12]
  • Commentary on fourth tetrad [13] to [16]

EBT compliant commentary on 16-APS 🌬️ 😤

A collection of notes from non EBT sources that are compliant with EBT interpretation of 16 APS

(STED 16-APS)

Idha, bhikkhave, bhikkhu
 Here, monks, a monk
[0.1] arañña-gato vā
 [0.1] (to the) wilderness-(he)-went, or
rukkha-mūla-gato vā
 (to the) tree-root-(he)-went, or
suññā-(a)gāra-gato vā
 (to the) empty-dwelling-(he)-went, **
[0.2] nisīdati
 [0.2] sits down
[0.3] pallaṅkaṃ ābhujitvā
 [0.3] (into)-cross-leg-posture (he)-bends,
[0.4] ujuṃ kāyaṃ paṇidhāya
 [0.4] straightened body (he)-aspires (to),
[0.5] pari-mukhaṃ satiṃ upaṭṭhapetvā.
 [0.5] Near-(the)-mouth, remembrance he-establishes.
[0.6] So sato-va assasati,
 [0.6] He, Always-a-rememberer, breathes in;
Sato-va passasati
 Always-a-rememberer, breathes out.

(1. kāyā-(a)nupassī)

Dīghaṃ vā assasanto ‘dīghaṃ assasāmī’ti pajānāti,
 (1) long ** breathing-in, 'long (I) am-breathing-in' (he) discerns;
dīghaṃ vā passasanto ‘dīghaṃ passasāmī’ti pajānāti;
 long ** breathing-out, 'long (I) am-breathing-out' (he) discerns;
rassaṃ vā assasanto ‘rassaṃ assasāmī’ti pajānāti,
 (2) short ** breathing-in, 'short (I) am-breathing-in' (he) discerns;
rassaṃ vā passasanto ‘rassaṃ passasāmī’ti pajānāti;
 short ** breathing-out, 'short (I) am-breathing-out' (he) discerns;
‘sabba-kāya-p-paṭisaṃvedī assasissāmī’ti sikkhati,
 (3) '(the) entire-body: sensitive-to (it), (I) will-breathe-in.' (Thus he) trains.
‘sabba-kāya-p-paṭisaṃvedī passasissāmī’ti sikkhati;
 (the) entire-body: sensitive-to (it), (I) will-breathe-out.' (Thus he) trains.
‘passambhayaṃ kāya-saṅkhāraṃ assasissāmī’ti sikkhati,
 (4) 'pacifying bodily-fabrication, (I) will-breathe-in.' (Thus he) trains.
‘passambhayaṃ kāya-saṅkhāraṃ passasissāmī’ti sikkhati.
 pacifying bodily-fabrication, (I) will-breathe-out.' (Thus he) trains.

(2. vedanā-(a)nupassī )

‘Pīti-p-paṭisaṃvedī assasissāmī’ti sikkhati,
 (5) 'rapture: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘pīti-p-paṭisaṃvedī passasissāmī’ti sikkhati;
 rapture: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘sukhap-paṭisaṃvedī assasissāmī’ti sikkhati,
 (6) 'pleasure: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘sukhap-paṭisaṃvedī passasissāmī’ti sikkhati;
 pleasure: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘citta-saṅkhārap-paṭisaṃvedī assasissāmī’ti sikkhati,
 (7) 'mental-fabrication: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘citta-saṅkhārap-paṭisaṃvedī passasissāmī’ti sikkhati;
 mental-fabrication: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘passambhayaṃ citta-saṅkhāraṃ assasissāmī’ti sikkhati,
 (8) 'pacifying mental-fabrication, (I) will-breathe-in.' (Thus he) trains.
‘passambhayaṃ citta-saṅkhāraṃ passasissāmī’ti sikkhati.
 pacifying mental-fabrication, (I) will-breathe-out.' (Thus he) trains.

(3. cittā-(a)nupassī)

‘Citta-p-paṭisaṃvedī assasissāmī’ti sikkhati,
 (9) '(the)-mind: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘citta-p-paṭisaṃvedī passasissāmī’ti sikkhati;
 (the)-mind: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘abhip-pa-modayaṃ cittaṃ assasissāmī’ti sikkhati,
 (10) 'abundantly-producing-mirth (in the)-mind, (I) will-breathe-in.' (Thus he) trains.
‘abhip-pa-modayaṃ cittaṃ passasissāmī’ti sikkhati;
 'abundantly-producing-mirth (in the)-mind, (I) will-breathe-out.' (Thus he) trains.
‘samādahaṃ cittaṃ assasissāmī’ti sikkhati,
 (11) 'undistract-ifying & lucid-ifying (the)-mind, (I) will-breathe-in.' (Thus he) trains.
‘samādahaṃ cittaṃ passasissāmī’ti sikkhati;
 undistract-ifying & lucid-ifying (the)-mind, (I) will-breathe-out.' (Thus he) trains.
‘vimocayaṃ cittaṃ assasissāmī’ti sikkhati,
 (12) 'liberating (the)-mind, (I) will-breathe-in.' (Thus he) trains.
‘vimocayaṃ cittaṃ passasissāmī’ti sikkhati;
 liberating (the)-mind, (I) will-breathe-out.' (Thus he) trains.

(4. dhammā-(a)nupassī)

‘a-niccā-(a)nupassī assasissāmī’ti sikkhati.
 (13) 'im-permanence: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘A-niccā-(a)nupassī passasissāmī’ti sikkhati;
 im-permanence: -contemplating (it, I) will-breathe-out.' (Thus he) trains.
‘vi-rāgā-(a)nupassī assasissāmī’ti sikkhati,
 (14) 'dis-passion: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘vi-rāgā-(a)nupassī passasissāmī’ti sikkhati;
 Dis-passion: -contemplating (it, I) will-breathe-out.' (Thus he) trains.
‘nirodhā-(a)nupassī assasissāmī’ti sikkhati,
 (15) 'cessation: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘nirodhā-(a)nupassī passasissāmī’ti sikkhati;
 cessation: -contemplating (it, I) will-breathe-out.' (Thus he) trains.
‘paṭinissaggā-(a)nupassī assasissāmī’ti sikkhati,
 (16) 'relinquishment: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘paṭinissaggā-(a)nupassī passasissāmī’ti sikkhati.
 relinquishment: -contemplating (it, I) will-breathe-out.' (Thus he) trains.

Intro

In step 3 of 16 APS, kāya = primarily the anatomical body. It’s more layered and nuanced to include other aspects beyond just the anatomical body, but primarily that’s the main meaning.

unjustified: body of breath

The English translations of kāya as “body of breath” has no EBT support. I’m not even sure there is late Abhidhamma support or justification. The English translators who wrongly translate kāya as “body of breath” are doing it based on the authority of Vism., a late Theravada work that
* contradicts early Theravada Abhidhamma,
* contradicts early Theravda canon such as KN Ps,
* contradicts a common sense straight forward reading of the EBT.
The EBT school of Sarvastivada, such as the SA and MA agamas supports the kāya as anatomical body (see b. Analayo’s books)
Sarvastivada commentary supports kāya as anatomical body in such works as Dhyana samadhi sutra, with such an explicit simile for step 3 of 16 APS there is no possible way it can mean anything other than physical body.
Sarvastivada Abhidhamma also has kāya as anatomical body
Early Theravada canonical/paracanonical such as KN Ps supports kāya as having two parts, a mental body and an anatomical body. But NOT a mental body divorced from a physical body. It says kaya refers to BOTH mental AND anatomical.
Early Theravada and early Te Abhidhamma, such as Vimt. (vimutti magga), on the 16 APS chapter, explicitly and clearly explains 16 APS in terms of anatomical body, and how to take it into the 4 jhanas. They explain the wind kasina has two types: A tactile sensation, and a visualization. Since breathing is a tactile experience, they rightly explain that one does not use the visual kasina of wind, but the tactile sensation kasina of wind as the entry into jhana with 16 APS. Vism acknowledges that wind kasina has 2 ways as Vimt, but with no explanation why one would ignore the tactile sensation, just tells you to go with a visual breath nimitta as the way into jhana, making it no different than earth kasina.
I believe other EBT schools represented by the Agamas like mahasanghika also support kaya as anatomical body. B. Analayo’s book would mention if the case was otherwise.
Summarizing with a timeline of EBT to modern times: Vism. seems to be the only one asserting kāya is only a mental body of breath completely divorced from physical. And unfortunately, the victors write the history books and exert a much stronger influence than would be justified if one were to carefully survey the evidence from the EBT schools. Hopefully with these clear pali+english audits freely available and easy to link to and cite, future translators can see the truth clearly for themselves.
400 BCE: Pari-nibbāna of the Buddha
237 BCE, KN Ps, canonical Theravada
1 CE, Vimutti-magga by Arahant Upatissa, early Theravada
409 CE Dhyāna Samādhi Sutra
411 CE Tattvasiddhi-sastra 成實論, treatise on various schools of Abhidhamma
500 CE, Visuddhi-magga, late Theravada Abhidhamma, “body/kāya” redefined as mind
1960 CE, Ajahn Lee (Dhammadaro), Theravada, Ajahn Mun Thai Forest tradition
2012 CE, Bhante Gunaratana, "Meditation on Perception", Theravada lineage from Sri Lanka
2013 CE, Thanissaro Bhikkhu, Theravada, Ajahn Mun Thai Forest tradition

breath is one type of body

The one place in the EBT people have tried to claim supports body as “body of breath” comes from this passage:
SN 54.10, MN 118, a breath body of air element is also part of the physical body
(i. Contemplation of the body)
7“Whenever (..a monk is doing steps 1 to 4 of STED 16 APS...)
—on that occasion the bhikkhu dwells contemplating the body in the body, ardent, ... (STED kāya anupassana of 4sp) ... in regard to the world.
taṃ kissa hetu?
 For what reason?
kāya-(a)ññatar-āhaṃ, ānanda, etaṃ vadāmi yadidaṃ —
 I call this a certain kind of body, Ānanda, that is,
assāsa-passāsaṃ.
 breathing in and breathing out.
this is called cherry picking and quoting out of context
When you examine the passage in full, what’s going on is the Buddha is trying to explain how the breath, which is a tactile sensation kinaesthetic experience, but doesn’t leave behind an obvious physical residue that is visible, how does that map into the 4sp (satipatthana) of body, feelings, mind, and Dhammas?
He’s is not saying you discard the physical body from your meditative awareness in 16 APS. What he’s saying is that the breath body, is also one (of many) types of bodies of the “physical”/rupa body.
Because otherwise, one might think if the main focus were the breath, that is not really “physical” like awareness of body postures, 31 body parts, etc. So the Buddha is reassuring them, saying, the breath is also part of the physical body, and you are not neglecting kaya anuassana by making the breath the primary focus of your attention.
Just as in the next tetrad, the Buddha says the “breath” is also a "vedana "among “vedanas”. So by focusing primarily on breath, you are not neglecting vedana-anupassana (of 4sp).
Similarly, buy focussing exclusively on breath, he explains how that also fulfills citta-anupassana and Dhamma-anupassana.
He is not saying kāya only means “body of breath” and you should discard the physical body from your meditative awareness.
If he had intended that meaning, he would definitely be more clear in explaining that. From all the evidence of various EBT schools, commentary, and various Abhdhamma schools, we have to conclude kāya is referring to anatomical body in 16 APS.
Consider the hypothetical scenario where Vism. is correct, that kāya means, only of “body of breath”, and one should actively ignore awareness of anything physical in our meditative experience. This would mean that:
KN Ps (just 200 years after the Buddha’s passing), early Abhidhamma, and all the other EBT schools, were fooled by the Buddha’s poor explanation and it took the wise and incomparable late Theravada Vism. commentators to correctly deduce what the Buddha truly meant, 1000 years later.
The Buddha is really poor at communicating. When he says body, most of the times he means “body”, but sometimes it means “mind only - completely ingnore the body!”
If you can’t trust the Buddha to accurately communicate what he means by “body”, what can you really trust about anything he says?
This is why it’s important to understand kāya in 16 APS correctly. If you have to use convoluted byzantine “reasoning” with cherry picking and quoting out of context, it’s probably not valid. Because if it is valid, it means the Buddha was a lousy communicator and you can’t trust that you understand any word he’s using. When he says “up”, sometimes he means “down”.

Simile of the bitter melon

What's the problem with translating kāya as "body of breath" when the Buddha already said that's a valid type of body?
I don’t think you understand the issue and what’s at stake. No one is saying that to focus entirely on the breath, that one would not be fulfilling the kāya of anupassana. The problem is late theravada in Vism. is not just saying that.
They’re effectively saying, by translating step 3’s kāya as “body of breath” instead of “body”, that ONLY body of breath fulfills kaya-anupassana for 16 APS and ALL OTHER BODIES the Buddha talked about in various 4sp contexxts ARE NOT LEGAL BODIES TO USE in 16 APS.
To give a simile, the Buddha as the consummate physician, left us a 16 step recipe for medicine to cure a nasty and fatal cancer. Step 3 calls for us to use an entire common household vegetable commonly used in cooking in the medicine. And a straightforward reading of the recipe is proven through actual empirical tests to work as advertised, curing cancer, by a straightforward reading of the EBT recipe. And it works for Te early commentary, Te Vinaya, Vimt., Sarvastivada EBT, Sarvastivada Vinaya, Sarvastivada Abhdhamma, early Te Abhidhamma.
Then along comes Vism. They say step 3 of the recipe does not mean all common vegetables that one typicaly uses in cooking. It must be a bitter melon. One must use the entire bitter melon, and only bitter melon. And they point to the Buddha’s own commentary that says, “A bitter melon is one type of common vegetable, and can be used for that common vegetable in the reciple.”
Do you understand now?
16 APS is the crown jewel of meditation topics, and the Buddha’s instruction on it are terse. You can not screw up step 3 that badly like Vism. and not incur massive heavy karmic consequences from that. So as a translator, even if you think bitter melon is the best vegetable of all, if you’re going to change the Buddha’s recipe to say, “only an entire bitter melon can be used” from “an entire common vegetable should be used”, you best be aware of the karmic consequences of doing that.
Hypothetically, let’s say I’m a translator, I’m a believer that bitter melon is the best. But I look at the evidence laid out, I see the empirical results of all the other EBT schools, that they got great results using vegetables other than bitter melon.
And let’s say I really love bitter melon, and I’m allergic to most other vegetables so can’t just try it out on myself and see if it works well. What should I do in the translation of the recipe? I really believe in bitter melon.
Understanding karma, and considering the effects of what would happen if I translated instructions for the cure for cancer to “bitter melon” when there’s lots of visible evidence from other people that “any common vegetable” would work for that medicine, wouldn’t I choose my words very carefully in the translation?
With kāya as "body", people have a choice between sweet potato, kabocha, carrots, celery, many types of delicious vegetables.
with kāya as "body of breath", this means you can only eat bitter melon. Every day, all day.

Commentary on preliminary steps [0.1] to [0.6]

Idha, bhikkhave, bhikkhu
 Here, monks, a monk
[0.1] arañña-gato vā
 [0.1] (to the) wilderness-(he)-went, or
rukkha-mūla-gato vā
 (to the) tree-root-(he)-went, or
suññā-(a)gāra-gato vā
 (to the) empty-dwelling-(he)-went, **
[0.2] nisīdati
 [0.2] sits down
[0.3] pallaṅkaṃ ābhujitvā
 [0.3] (into)-cross-leg-posture (he)-bends,
[0.4] ujuṃ kāyaṃ paṇidhāya
 [0.4] straightened body (he)-aspires (to),
[0.5] pari-mukhaṃ satiṃ upaṭṭhapetvā.
 [0.5] Near-(the)-mouth, remembrance he-establishes.
[0.6] So sato-va assasati,
 [0.6] He, Always-a-rememberer, breathes in;
Sato-va passasati
 Always-a-rememberer, breathes out.

Commentary on first tetrad steps [1] to [4]

Dīghaṃ vā assasanto ‘dīghaṃ assasāmī’ti pajānāti,
 (1) long ** breathing-in, 'long (I) am-breathing-in' (he) discerns;
dīghaṃ vā passasanto ‘dīghaṃ passasāmī’ti pajānāti;
 long ** breathing-out, 'long (I) am-breathing-out' (he) discerns;
rassaṃ vā assasanto ‘rassaṃ assasāmī’ti pajānāti,
 (2) short ** breathing-in, 'short (I) am-breathing-in' (he) discerns;
rassaṃ vā passasanto ‘rassaṃ passasāmī’ti pajānāti;
 short ** breathing-out, 'short (I) am-breathing-out' (he) discerns;
‘sabba-kāya-p-paṭisaṃvedī assasissāmī’ti sikkhati,
 (3) '(the) entire-body: sensitive-to (it), (I) will-breathe-in.' (Thus he) trains.
‘sabba-kāya-p-paṭisaṃvedī passasissāmī’ti sikkhati;
 (the) entire-body: sensitive-to (it), (I) will-breathe-out.' (Thus he) trains.
‘passambhayaṃ kāya-saṅkhāraṃ assasissāmī’ti sikkhati,
 (4) 'pacifying bodily-fabrication, (I) will-breathe-in.' (Thus he) trains.
‘passambhayaṃ kāya-saṅkhāraṃ passasissāmī’ti sikkhati.
 pacifying bodily-fabrication, (I) will-breathe-out.' (Thus he) trains.

step 3: entire physical body

400 BCE: Pari-nibbāna of the Buddha

A chronological reference point. For EBT scriptural citations on anatomical body in step 3,
see article: 4nt→ STED → 16 APS → The Buddha's commentary on 16 APS

237 BCE, KN Ps, canonical Theravada

.
 .

16 APS step 3 “entire body he experiences”

KN Ps = Paṭi-sambhidā-magga
♦ 170. kathaṃ “sabbakāyapaṭisaṃvedī
 42. (§48). “`Experiencing the whole body,’
assasissāmī”ti sikkhati,
 I shall breathe in, thus he trains himself;
“sabbakāyapaṭisaṃvedī
 `experiencing the whole body,’
passasissāmī”ti sikkhati?
 I shall breathe out, thus he trains himself.”
kāyoti dve kāyā —
 “Body”: There are two bodies—
nāma-kāyo ca rūpa-kāyo ca.
 the mentality-body and the materiality-body.

nāma kāya

katamo nāma-kāyo?
 What is the mentality body?
vedanā, saññā, cetanā,
 Feeling, perception, volition,
phasso, manasikāro,
 sense-impression, attention,
nāmañ-ca nāma-kāyo ca,
 mentality and the mentality-body—
ye ca vuccanti citta-saṅkhārā —
 and those (things) which are called the mental formations—
ayaṃ nāmakāyo.
 this is the mentality-body. 176

rūpa kāya

katamo rūpa-kāyo?
 What is materialiy body?
cattāro ca mahā-bhūtā,
 The four great primaries
catunnañ-ca mahā-bhūtānaṃ upādāya-rūpaṃ,
 and the materiality derived from the four great primaries—
assāso ca passāso ca,
 in-breath and out-breath and
nimittañ-ca upanibandhanā,
 the sign for the binding (of mindfulness)—
ye ca vuccanti kāya-saṅkhārā —
 and those (things) which are called the bodily formations—
ayaṃ rūpa-kāyo.
 this is the materiality-body.177

1 CE, Vimutti-magga by Arahant Upatissa, early Theravada

(Nimitta “image” is tactile perception, not visual!)

… To the yogin who attends to the incoming breath with mind that is cleansed of the nine lesser defilements the image arises with a pleasant feeling similar to that which is produced in the action of spinning cotton or silk cotton. Also, it is likened to the pleasant feeling produced by a breeze.
Thus in breathing in and out, air touches the nose or the lip and causes the setting-up of air perception mindfulness. This does not depend on colour or form.
This is called the image (Nimitta). If the yogin develops the image (Nimitta) and increases it at the nose-tip, between the eye-brows, on the forehead or establishes it in several places,
he feels as if his head were rilled with air.
Through increasing in this way his whole body is charged with bliss (sukha).
This is called perfection.
...

(correct respiration Nimitta will trigger Pīti & sukha)

If his mind becomes clear, the yogin does not experience confusion. He attends to respiration and he does not cause the arising of other perceptions. Meditating thus he is able to end confusion and acquire the subtle image (Nimitta). And he attends to respiration with mind that is free. That image (Nimitta) is free. Because that image (Nimitta) is free, desire arises. Desire being free, that yogin attends to respiration and becomes joyful. Desire and joy being free, he attends to respiration with equipoise. Equipoise, desire and joy being free, he attends to respiration, and his mind is not disturbed. If his mind is not disturbed, he will destroy the hindrances, and arouse the meditation (jhāna) factors. Thus this yogin will reach the calm and sublime fourth meditation, jhāna. This is as was fully taught above.
...

(key marker for each jhāna while in 16 APS)

The experiencing of joy (Pīti) is the state of the second meditation, jhāna. The experiencing of bliss (sukha) is the state of the third meditation, jhāna. The experien- cing of the mind is the state of the fourth meditation, jhāna.

409 CE Dhyāna Samādhi Sutra

Dhyāna Samādhi Sutra (corresponds with Ānāpānā step 3, sabba kāya patisamvedi)
 Dhyāna Samādhi Sutra (chinese to english trans. By Dr. William Chu)
T15n0614_p0275b25(08)║念諸息遍身。亦念息出入。
 “One is mindfully aware of various breaths suffusing the whole body, as one attends to the exhalation and inhalation of the breath.
T15n0614_p0275b26(05)║悉觀身中諸出息入息。
 As one pervasively observes the various kinds of inhalation and exhalation inside the body,
T15n0614_p0275b27(14)║覺知遍至身中乃至足指遍諸毛孔如水入沙。
 one becomes aware and comprehends what is happening throughout the body, up to and including one’s toes and pores—[awareness] pervades as if water seeps into sands.
T15n0614_p0275b28(13)║息出覺知從足至髮遍諸毛孔亦如水入沙。譬如[夢-夕+棐]囊入出皆滿。
 In the same way, with [each] out-breath, awareness and understanding pervade—from the toes to the hairs, permeating all the pores—as if water seeps into sands. Just like a sack that is completely filled from its bottom to its opening,
T15n0614_p0275b29(05)║口鼻風入出亦爾。觀身周遍見風行處。
 so too should one experience the body being saturated this way with [each] in-breath coming in from mouth [and/or] nose.
T15n0614_p0275c01(07)║如藕根孔亦如魚網。復心非獨口鼻觀息入出。
 One should perceive that throughout the body, where ‘wind’ traverses, it is as if it traverses through the holes of a lotus root; it is as if it traverses through the eyes of a fish net.
T15n0614_p0275c02(06)║一切毛孔及九孔中。亦見息入息出。
 Furthermore, one should not just perceive the breath as going in and out of one’s mouth [and/or] nose; one should also see that the breath comes in and out from all the pores and from the nine orifices of the body.
T15n0614_p0275c03(09)║是故知息遍諸身
 For this reason, one should understand that the breath pervades throughout the body."

411 CE Tattvasiddhi-sastra 成實論, treatise on various schools of Abhidhamma

Taisho #T1646
念息遍身除諸身行--
 "One should be mindful of the breath as it pervades the whole body, all the while ridding of bodily formations."
Dr. Chu comments: Here, the "body" is clearly the corporeal body and not the "breath body"

500 CE, Visuddhi-magga, late Theravada Abhidhamma, “body/kāya” redefined as mind

Note Vism. Is the only entry in this section that deviates from the physical body as kāya, and is included as a chronological reference point to show when later Theravada deviates from early Theravada and EBT.
Whereas the early Theravada KN Ps and Vimt. follow the straightforward EBT reading of kāya as physical body which consists of 4 elements and 31 body parts in 16 APS and jhāna, Vism. contradicts the straightforward EBT interpretation and treats kāya in these contexts as a “breath body” and “body of mental aggregates”.

1960 CE, Ajahn Lee (Dhammadaro), Theravada, Ajahn Mun Thai Forest tradition

(method 1 excerpts, from "Keeping the Breath in Mind")
...The body will be light, like fluff. The mind will be rested and refreshed—supple, solitary, and self-contained. There will be an extreme sense of physical pleasure and mental ease...
(method 2 excerpts)
...As soon as you find that your breathing feels comfortable, let this comfortable breath sensation spread to the different parts of the body. To begin with, inhale the breath sensation at the base of the skull and let it flow all the way down the spine. Then, if you are male, let it spread down your right leg to the sole of your foot, to the ends of your toes, and out into the air. Inhale the breath sensation at the base of the skull again and let it spread down your spine, down your left leg to the ends of your toes and out into the air. (If you are female, begin with the left side first, because the male and female nervous systems are different.)
Then let the breath from the base of the skull spread down over both shoulders, past your elbows and wrists, to the tips of your fingers, and out into the air.
Let the breath at the base of the throat spread down the central nerve at the front of the body, past the lungs and liver, all the way down to the bladder and colon.
Inhale the breath right at the middle of the chest and let it go all the way down to your intestines.
Let all these breath sensations spread so that they connect and flow together, and you’ll feel a greatly improved sense of well-being.
...
6. Spread your awareness—your sense of conscious feeling—throughout the entire body.
7. Unite the breath sensations throughout the body, letting them flow together comfortably, keeping your awareness as broad as possible. Once you’re fully aware of the aspects of the breath you already know in your body, you’ll come to know all sorts of other aspects as well. The breath, by its nature, has many facets: breath sensations flowing in the nerves, those flowing around and about the nerves, those spreading from the nerves to every pore. Beneficial breath sensations and harmful ones are mixed together by their very nature.
...
(Under the Jhāna chapter, all four jhānas explicitly reference 4 elements and 31 physical body parts)

2012 CE, Bhante Gunaratana, "Meditation on Perception", Theravada lineage from Sri Lanka

Excerpt from chapter 13, his comments on the first tetrad, first four steps of 16 APS
The focus of this first meditation is the “breath-body,” the form or body that arises as we breathe in and breathe out. We experience the breath as a body when its form or shape gives rise to pressure, release, and other sensations of touch in the nose, lungs, and abdomen. The breath-body, the sutta continues, is a “body among the bodies.” In other words, it is one of the many bodies, or parts, that make up the human form. Full awareness and pure mindfulness of even one of the thirty-two parts of the body can be enough for some meditators to achieve insight.
Moreover, when we meditate on the breath-body as a “body among the bodies,” we remain focused on the body in and of itself, seeing the body as simply part of the form aggregate, without the usual colorations of attachment or “covetousness” for the pleasant parts and “grief” or aversion toward the unpleasant or decaying parts. Like all forms, the body comes into being, remains present for a time, and then passes away. Since it is not “myself,” there is no reason for us to feel attached to the body or to grieve when the body gets sick or decays as a result of aging.
In addition, we recognize that the breath, like all other bodies, is made up of elements—earth, water, air, and fire. We can recognize the four elements by their characteristic functions. The function of the earth element is to generate hardness or softness. The sensations we experience in the body when we breathe are due to the presence of the hardness or softness of the breath’s earth element. Similarly, we notice that the breath feels dry when its water element is low. When we are aware of moisture in the breath, it is because the water element is high. The function of the air element is motion and energy. We experience the movement of the breath because of its air element. The temperature of the breath is due to its fire element. Heat fluctuates. When the heat element in the breath is high, we call the breath hot. When it drops down, we call the breath cool.
In addition to the four elements, the parts of the body—including the breath—are described as internal or external. The elements inside the body are internal; those outside are external. If we think about this distinction, it may occur to us that the breath that we have inhaled is internal. When we exhale, this internal breath mixes with the external air. Then the breath is external. We might also say that the internal body is inhaling, and the external body is exhaling.
In the Maharahulovada Sutta, the Buddha explained the meaning of the words “internal” and “external” as they apply to the four elements of the body. In terms of the air element, he said, “Whatever internally, belonging to oneself, is air. . .that is up-going winds, down-going winds, winds in limbs, in-breath and out-breath. . .this is called the internal air element.” Moreover, the Buddha explained, “Both the internal air element and the external air element are simply air element.” This point is important because of our tendency to cling to things we perceive as belonging to us. Seen with “proper wisdom,” we recognize that even the air we inhale—the internal air—“is not mine, this I am not, and this is not my self. When one sees it thus as it actually is. . .one becomes disenchanted with the air element and makes the mind dispassionate toward the air element.”

7sb awakening factor passadhi-bojjhanga contains physical body

... This energy causes the fourth factor, joy or rapture, to arise in the meditator, which by repeated practice comes to fulfillment as a factor of enlightenment. Joy makes the body and mind tranquil and arouses, develops, and brings to fulfillment the tranquility factor of enlightenment. ...

2013 CE, Thanissaro Bhikkhu, Theravada, Ajahn Mun Thai Forest tradition

(Excerpts from "With Each and Every Breath")
(chapter on "Basic Instructions")
When the blatant sensations of breathing are comfortable, expand your awareness to different parts of the body to observe more subtle breathing sensations.
You can do this section-by-section, in any order you like, but in the beginning try to be systematic so that you cover the entire body.
{...Detailed 4 element and 31 body part section by section exploration follows...}
5. Spread your awareness from that spot so that it fills the body through every in-and-out breath.
Think of a lit candle in the middle of an otherwise dark room. The flame of the candle is in one spot, but its light fills the entire room. You want your awareness to be centered but broad in just the same way. Your sense of awareness may have a tendency to shrink—especially as you breathe out—so remind yourself with every breath: “whole body breathing in, whole body breathing out.” This full-body awareness helps to keep you from getting drowsy when the breath gets comfortable, and from losing focus as the breath gets more subtle.
6. Think of the breath energy coursing through the whole body with every in-and-out breath.
Let the breath find whatever rhythm or texture feels best. Think of all the breath energies connecting with one another and flowing in harmony. The more fully they’re connected, the more effortless your breathing will be. If you have a sense that the breath-channels are open during the in-breath but close during the out-breath, adjust your perception to keep them open throughout the breathing cycle.
Then simply maintain that sense of whole-body breathing throughout the remainder of your meditation. If the breath grows still, don’t worry. The body will breathe if it needs to. When the mind is still, the brain uses less oxygen, so the oxygen that the body receives passively—through the lungs and perhaps through the relaxed pores (anatomists have differing opinions on this)—will be enough to serve its needs. At the same time, however, don’t force the breath to stop. Let it follow its own rhythm. Your duty is simply to maintain a broad, centered awareness and to allow the breath to flow freely throughout the body.
If you find that you lose focus when you spread your awareness through the body, you can return to the survey of the different parts, try a meditation word, or simply stay focused on one point until you feel ready to try full-body awareness again.

step 4: tranquilizing bodily processes

Commentary on second tetrad steps [5] to [8]

‘Pīti-p-paṭisaṃvedī assasissāmī’ti sikkhati,
 (5) 'rapture: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘pīti-p-paṭisaṃvedī passasissāmī’ti sikkhati;
 rapture: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘sukhap-paṭisaṃvedī assasissāmī’ti sikkhati,
 (6) 'pleasure: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘sukhap-paṭisaṃvedī passasissāmī’ti sikkhati;
 pleasure: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘citta-saṅkhārap-paṭisaṃvedī assasissāmī’ti sikkhati,
 (7) 'mental-fabrication: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘citta-saṅkhārap-paṭisaṃvedī passasissāmī’ti sikkhati;
 mental-fabrication: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘passambhayaṃ citta-saṅkhāraṃ assasissāmī’ti sikkhati,
 (8) 'pacifying mental-fabrication, (I) will-breathe-in.' (Thus he) trains.
‘passambhayaṃ citta-saṅkhāraṃ passasissāmī’ti sikkhati.
 pacifying mental-fabrication, (I) will-breathe-out.' (Thus he) trains.

step 8: calming mental fabrication

Commentary on third tetrad steps [9] to [12]

‘Citta-p-paṭisaṃvedī assasissāmī’ti sikkhati,
 (9) '(the)-mind: -sensitive-to-it, (I) will-breathe-in.' (Thus he) trains.
‘citta-p-paṭisaṃvedī passasissāmī’ti sikkhati;
 (the)-mind: -sensitive-to-it, (I) will-breathe-out.' (Thus he) trains.
‘abhip-pa-modayaṃ cittaṃ assasissāmī’ti sikkhati,
 (10) 'abundantly-producing-mirth (in the)-mind, (I) will-breathe-in.' (Thus he) trains.
‘abhip-pa-modayaṃ cittaṃ passasissāmī’ti sikkhati;
 'abundantly-producing-mirth (in the)-mind, (I) will-breathe-out.' (Thus he) trains.
‘samādahaṃ cittaṃ assasissāmī’ti sikkhati,
 (11) 'undistract-ifying & lucid-ifying (the)-mind, (I) will-breathe-in.' (Thus he) trains.
‘samādahaṃ cittaṃ passasissāmī’ti sikkhati;
 undistract-ifying & lucid-ifying (the)-mind, (I) will-breathe-out.' (Thus he) trains.
‘vimocayaṃ cittaṃ assasissāmī’ti sikkhati,
 (12) 'liberating (the)-mind, (I) will-breathe-in.' (Thus he) trains.
‘vimocayaṃ cittaṃ passasissāmī’ti sikkhati;
 liberating (the)-mind, (I) will-breathe-out.' (Thus he) trains.

Commentary on fourth tetrad [13] to [16]

‘a-niccā-(a)nupassī assasissāmī’ti sikkhati.
 (13) 'im-permanence: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘A-niccā-(a)nupassī passasissāmī’ti sikkhati;
 im-permanence: -contemplating (it, I) will-breathe-out.' (Thus he) trains.
‘vi-rāgā-(a)nupassī assasissāmī’ti sikkhati,
 (14) 'dis-passion: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘vi-rāgā-(a)nupassī passasissāmī’ti sikkhati;
 Dis-passion: -contemplating (it, I) will-breathe-out.' (Thus he) trains.
‘nirodhā-(a)nupassī assasissāmī’ti sikkhati,
 (15) 'cessation: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘nirodhā-(a)nupassī passasissāmī’ti sikkhati;
 cessation: -contemplating (it, I) will-breathe-out.' (Thus he) trains.
‘paṭinissaggā-(a)nupassī assasissāmī’ti sikkhati,
 (16) 'relinquishment: -contemplating (it, I) will-breathe-in.' (Thus he) trains.
‘paṭinissaggā-(a)nupassī passasissāmī’ti sikkhati.
 relinquishment: -contemplating (it, I) will-breathe-out.' (Thus he) trains.