CC Madhya 25.133
agra ātmātmanāṁ vibhuḥ
bhagavān — the Supreme Personality of Godhead; ekaḥ — only; āsa — was; idam — this universe; agre — before (before the creation of this cosmic manifestation); ātmā — the living force; ātmanām — of all the living entities; vibhuḥ — the Supreme Lord; ātma — of the Supreme; icchā — the will; anugatau — according to; ātmā — the Supersoul; anānā-mati-upalakṣaṇaḥ — who is not realized by persons having many angles of vision.
“ ‘Before the cosmic manifestation was created, the creative propensity was merged in the Supreme Lord’s person. At that time all potencies and manifestations were preserved in His personality. The Lord is the cause of all causes, and He is the all- pervading, self-sufficient person. Before the creation, He existed with His spiritual potency in the spiritual world, wherein various Vaikuṇṭha planets are manifested.’
This is a quotation from Śrīmad-Bhāgavatam (3.5.23).