Bhagavad Gita Chapter 9.7
sarva-bhūtāni kaunteya
prakṛtiḿ yānti māmikām
kalpa-kṣaye punas tāni
kalpādau visṛjāmy aham
Translation
O son of Kunti, at the end of the millennium all material manifestations enter into My nature, and at the beginning of another millennium, by My potency, I create them again.