Srimad Bhagavatam Canto 09, Chapter 18, Text 49

SB 9.18.49

yasminn idam viracitam
 vyomniva jaladavalih
naneva bhati nabhati
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The Supreme Lord, Vasudeva, who created the cosmic manifestation, exhibits Himself as all-pervading, like the sky that holds clouds. And when the creation is annihilated, everything enters into the Supreme Lord, Visnu, and varieties are no longer manifested.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
As stated by the Lord Himself in Bhagavad-gita (7.19):
bahunam janmanam ante
 jñanavan mam prapadyate
vasudevah sarvam iti
 sa mahatma sudurlabhah
“After many births and deaths, he who is actually in knowledge surrenders unto Me, knowing Me to be the cause of all causes and all that is. Such a great soul is very rare.” The Supreme Personality of Godhead, Vasudeva, is one with the Supreme Brahman, the Supreme Absolute Truth. Everything is in Him in the beginning, and at the end all manifestations enter into Him. He is situated in everyone’s heart (sarvasya caham hrdi sannivistah). And from Him everything has emanated (janmady asya yatah). All material manifestations, however, are temporary. The word svapna means “dreams,” maya means “illusion,” and manoratha means “mental creations.” Dreams, illusions and mental creations are temporary. Similarly, all material creation is temporary, but Vasudeva, the Supreme Personality of Godhead, is the eternal Absolute Truth.