Bhagavad Gita 9.7

सर्वभूतानि कौन्तेय प्रकृतिं यान्ति मामिकाम् |
कल्पक्षये पुनस्तानि कल्पादौ विसृजाम्यहम्

Translation

At the end of one kalp, all living beings merge into My primordial material energy. At the beginning of the next creation, O son of Kunti, I manifest them again.