Bhagavad Geeta Chapter 9 - The Royal Secret
6. As the mighty wind, moving everywhere, rests always in space (the akasa),even so, know you, all beings rest in Me.
Verse 7 & 8
7. All beings, O Kaunteya! (O son of Kunti!) Go into my prakrti (nature) at the end of a kalpa; I send them forth again at the beginning of the next kalpa.
8. Animating my prakrti, I, again and again send forth all this multitude of beings, helpless by the force of nature (prakrti).