SB 3.6.6

hiraṇmayaḥ sa puruṣaḥ
 sahasra-parivatsarān
āṇḍa-kośa uvāsāpsu
 sarva-sattvopabṛṁhitaḥ
Synonyms: 
hiraṇmayaḥ — the Garbhodakaśāyī Viṣṇu, who also assumes the virāṭ-rūpa; saḥ — He; puruṣaḥ — incarnation of Godhead; sahasra — one thousand; parivatsarān — celestial years; āṇḍa-kośe — within the global universe; uvāsa — resided; apsu — on the water; sarva-sattva — all living entities lying with Him; upabṛṁhitaḥ — so spread.
Translation: 
The gigantic virāṭ-puruṣa, known as Hiraṇmaya, lived for one thousand celestial years on the water of the universe, and all the living entities lay with Him.
Purport: 

After the Lord entered each and every universe as the Garbhodakaśāyī Viṣṇu, half of the universe was filled with water. The cosmic manifestation of the planetary systems, outer space, etc., which are visible to us, is only one half of the complete universe. Before the manifestation takes place and after the entrance of Viṣṇu within the universe, there is a period of one thousand celestial years. All the living entities injected within the womb of the mahat-tattva are divided in all universes with the incarnation of Garbhodakaśāyī Viṣṇu, and all of them lie down with the Lord until Brahmā is born. Brahmā is the first living being within the universe, and from him all other demigods and living creatures are born. Manu is the original father of mankind, and therefore, in Sanskrit, mankind is called mānuṣya. Humanity in different bodily qualities is distributed throughout the various planetary systems.