B. Thanissaro Notes
1. “Clearly saw insight”: In Pali, this is vipassanaṁ vipassi, which could be translated literally as “clearly saw clear seeing” or “insighted insight.” The Commentary states that the half-month mentioned here refers to the half month between Ven. Sāriputta’s ordination and his attainment of arahantship, described in MN 74. These two suttas treat Sāriputta’s attainment from two different perspectives. This sutta shows it from the standpoint of his mastery of the four jhānas and the formless attainments based on the fourth jhāna. That sutta shows it as occurring when he starts reflecting on a point while listening to a discourse that the Buddha is giving to his nephew. To put the two suttas together, we can infer that prior to the discourse given in MN 74, Sāriputta had mastered the dimension of neither perception nor non-perception. While listening to the discourse, he reflected on the point that the Buddha recommended abandoning all mental dharma-[phenomena] through direct knowledge. This would have led him to the cessation of perception and feeling (during which he would not be listening to the discourse) and so to awakening.
2. Reading viññāṇaṁ with the Thai edition of the Canon. The Burmese and PTS editions read cittaṁ, which could mean “mind” or “intent” (as in the four bases of success).
3. Reading passaddhattā with the Burmese edition. The Thai edition reads, parisuddhatā, “through purity.” The Sinhalese edition reads pasiddhatā, which would mean “empowerment” (?—this term is not listed in the PTS Dictionary). The PTS edition reads passi vedanā, which is unintelligible.
4. Notice that, with each of the previous levels of attainment, Sāriputta was able to ferret out the various mental dharma-[phenomena] arising there while he was still in the attainment. With this attainment and the following one, however, he was not able to analyze the mental dharma-[phenomena] present and absent there until after he had left the attainment. The difference here is related to the point made in AN 9:36 that all the attainments up through the dimension of nothingness are “perception-attainments.” And that, “As far as the perception-attainments go, that is as far as gnosis-penetration goes. As for these two dimensions—the attainment of the dimension of neither perception nor non-perception & the attainment of the cessation of perception & feeling—I tell you that they are to be rightly explained by those monks who are meditators, skilled at attainment, skilled at attainment-emergence, who have attained & emerged in dependence on them.”
For a discussion of how insight can be developed in the context of jhāna, see The Wings to awakening, IIIF.
5. For a more detailed description of what a meditator experiences on emerging from the cessation of perception and feeling, see MN 44.
See also: MN 43; MN 52; MN 140; AN 5:28; AN 9:36