SB 11.24.10

tasminn ahaṁ samabhavam
 aṇḍe salila-saṁsthitau
mama nābhyām abhūt padmaṁ
 viśvākhyaṁ tatra cātma-bhūḥ
tasmin — within that; aham — I; samabhavam — appeared; aṇḍe — in the egg of the universe; salila — in the water of the Causal Ocean; saṁsthitau — which was situated; mama — My; nābhyām — from the navel; abhūt — arose; padmam — a lotus; viśva-ākhyam — known as universal; tatra — in that; ca — and; ātma-bhūḥ — self-born Brahmā.
I Myself appeared within that egg, which was floating on the causal water, and from My navel arose the universal lotus, the birthplace of self-born Brahmā.

The Supreme Lord here describes His appearance in His transcendental pastime form of Śrī Nārāyaṇa. Lord Nārāyaṇa enters within the universe but does not give up His purely transcendental body of knowledge and bliss. Lord Brahmā, however, born from the Lord’s navel lotus, has a material body. Although Lord Brahmā is the most powerful mystic, his body, which pervades all material existence, is material, whereas the body of the Supreme Lord Hari, Nārāyaṇa, is always transcendental.