At the end of the millennium, when the Personality of Godhead, Lord Nārāyaṇa, lay down within the water of devastation, Brahmā began to enter into Him along with all creative elements, and I also entered through His breathing.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
प्रयुज्यमाने मयि तां शुद्धां भागवतीं तनुम् । आरब्धकर्मनिर्वाणो न्यपतत्पाञ्चभौतिकः
prayujyamāne mayi tāṃ śuddhāṃ bhāgavatīṃ tanum | ārabdhakarmanirvāṇo nyapatatpāñcabhautikaḥ
SB 1.6.29