I am the Self, O Gudakesa*,
dwelling in the Hearts of all beings.
I am the beginning and the middle and the end of all beings.
-- Bhagavad Gita, X: 20
[* - Arjuna]
The Supreme Lord is situated in everyone's heart, O Arjuna,
and is directing the wanderings of all living entities,
who are seated as on a machine, made of the material energy*
-- Bhagavad Gita, XVIII: 61
[* Maya or illusion]
Please see The Song Celestial.