Bhagavatapurana 1.6.30

1.6.30

kalpānta idam ādāya śayāne 'mbhasyudanvataḥ /
śiśayiṣoranuprāṇaṃ viviśe 'ntarahaṃ vibhoḥ //

30. I entered along with His breath into Brahma (Chaturmukha) who was about to retire into the Supreme Being, when at the end (during the deluge), He sleeps on the waters of the sea, (having withdrawn all this world into Himself).