SB 7.9.34
tat-sambhavah kavir ato ’nyad apasyamanas
tvam bijam atmani tatam sa bahir vicintya
navindad abda-satam apsu nimajjamano
jate ’nkure katham uhopalabheta bijam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
From that great lotus flower, Brahma was generated, but Brahma certainly could see nothing but the lotus. Therefore, thinking You to be outside, Lord Brahma dove into the water and attempted to find the source of the lotus for one hundred years. He could find no trace of You, however, for when a seed fructifies, the original seed cannot be seen.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
This is the description of the cosmic manifestation. The development of the cosmic manifestation is like the fructification of a seed. When cotton is transformed into thread, the cotton is no longer visible, and when the thread is woven into cloth, the thread is no longer visible. Similarly, it is perfectly correct that when the seed that had generated from the navel of Garbhodakasayi Visnu became manifested as the cosmic creation, one could no longer understand where the cause of the cosmic manifestation is. Modern scientists have tried to explain the origin of creation by a chunk theory, but no one can explain how such a chunk might have burst. The Vedic literature, however, explains clearly that the total material energy was agitated by the three modes of material nature because of the glance of the Supreme Lord. In other words, in terms of the chunk theory, the bursting of the chunk was caused by the Supreme Personality of Godhead. Thus one must accept the supreme cause, Lord Visnu, as the cause of all causes.