The elephant is sati. Always remembers what he needs to do, never forgets. The rider represents the wise gate keeper from AN 7.67, the frontier fortress. AN 5.139: “And how is a king’s elephant resilient to ...fearful sights... horrible smells ... terrifying sounds ... physical pain ...? ... having gone into battle, he is pierced by a flight of arrows, two flights, three flights, four flights, five flights of arrows, but he doesn’t falter or faint, he steels himself and engages in the battle...
That resilience (khamo) is the key characteristic of samadhi. Not "stillness". Pacification and serenity are important NUTRIMENTS of samadhi, but they are not equivalent to it. There are many 'samadhi suttas' in the EBT, but only one sutta titled "samma samadhi" (AN 5.113). Its central focus is Khamo/resilience, not "stillness". Samadhi is not a trance, not a state where you can't think, can not act, and not form an intention. Samadhi is dynamic. It can appear quiescent, but it's poised and alert, not in an trance. When you're in samadhi, you may appear very still, but you ready. You is ready. You be ready, on a moment's notice, to fight the asavas and break through to nirvana. Samadhi is the pinnacle 🌄 of lucidity, of mental power. AN 5.113: “possesssing five-of-these qualities,
(a) monk [is] capable (of) dwelling in righteous-undistractable-lucidity,
Which five? (a) monk is resilient to forms, sounds, odors, tastes, and tactile-objects,
All of his books are free, all of his views on Jhāna are EBT compliant: http://www.dhammatalks.org
Bhante Henepola Gunaratana
Should we come out of Jhāna to practice Vipassanā?
Beyond Mindfulness in Plain English (from wisdom pub)
His older published books and writings on Jhāna follow Vism. and is NOT EBT compliant, so beware!