Śrīmad-Bhāgavatam · Text 1.3.2
Who is speaking and story frame
यस्याम्भसि शयानस्य योगनिद्रां वितन्वत: ।
नाभिह्रदाम्बुजादासीद्ब्रह्मा विश्वसृजां पति: ॥ २ ॥
yasyāmbhasi śayānasya
yoga-nidrāṁ vitanvataḥ
nābhi-hradāmbujād āsīd
brahmā viśva-sṛjāṁ patiḥ
A part of the puruṣa lies down within the water of the universe, from the navel lake of His body sprouts a lotus stem, and from the lotus flower atop this stem, Brahmā, the master of all engineers in the universe, becomes manifest.
Read Śrīla Prabhupāda's purport on Vedabase.io