He who, dwelling in deep sleep, whom deep sleep does not know, whose body is deep sleep, who controls deep sleep from within —He is your Ātman, the Inner Ruler, the Immortal.

Suṣupti (deep dreamless sleep) is the state closest to our pure nature: without objects, without thoughts, without duality. And yet, upon waking we “know” that we slept deeply, which implies there was a witness. In our yoga practice, this is the state of kaivalya, of non-dual unity. The antaryāmin here is not absence but presence in the form of pure possibility. When we emerge from deep sleep, it is He who re-constructs the waking world.