Yoga-nidra (the Lord's mystic slumber)

Yoga-nidra is the Lord's mystic slumber: the yogic trance spread by the purusha-avatara reclining on the causal waters (SB 1.3.2), during which Brahma arises from the navel-lotus; the Devi-mahatmya's Yoga-nidra conception is this idea's later development.

Śrīmad Bhāgavata Mahāpurāṇa 1.3.2 — Sanskrit Wikisource (pinned oldid=369178)