The Inner Controller
Brahman as the indwelling presence guiding from within.
The Antaryamin is Brahman as the inner controller dwelling in all beings, directing them from within yet unknown to them. It is the silent witness and guide.
He who dwells in all beings, yet is within all beings, whom no being knows, whose body is all beings, who controls all beings from within - He is your Self, the Inner Controller, the Immortal.
This reveals Brahman as both transcendent and immanent.
Brihadaranyaka Upanishad