Mbh 3.202.3a

“Markandeya said, ‘O monarch, know everything as it happened, O ruler of men, as I narrate the particulars truly, O thou of great wisdom! When the world became one broad expanse of water and creatures mobile and immobile were destroyed, when, O bull of the Bharata race, the entire creation came to its end. He who is the Source and Creator of the Universe, viz., the Eternal and unfading Vishnu, He who is called by Munis crowned with ascetic success as the Supreme Lord of the Universe, that Being of great holiness, then lay in Yoga sleep on the wide hood of the Snake Sesha of immeasurable energy, and the Creator of the Universe, that highly-blessed and holy Hari, knowing no deterioration, lay on the hood of that Snake encircling the whole Earth and as the Deity lay asleep on that bed, a lotus, endued with great beauty and effulgence equal unto that of the Sun, sprang from his navel. And from that lotus possessed of effulgence like unto the Sun’s, sprang the Grandsire Brahma, that lord of the worlds who is the four Vedas, who hath four forms and four faces, who is invincible in consequence of his own energy and who is endued with mighty strength and great prowess and as the Lord Hari of wondrous frame, possessed of great lustre and decked with a crown and the Kaustubha gem and attired in purple silk, lay stretched for many a yojana on that excellent bed furnished by the hood of the snake itself extending far and wide, blazing, O king, in his beauty and the lustre of his own body like a thousand Suns concentrated in one mass.