Bhagwad Gita
Chapter 9, Verse 7
सर्वभूतानि कौन्तेय प्रकृतिं यान्ति मामिकाम्।
कल्पक्षये पुनस्तानि कल्पादौ विसृजाम्यहम्।।9.7।।
O son of Kunti, at the end of the millennium every material manifestation enters into My nature, and at the beginning of another millennium, by My potency I again create.