SB 3.6.8
esa hy asesa-sattvanam
atmamsah paramatmanah
adyo ’vataro yatrasau
bhuta-gramo vibhavyate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The gigantic universal form of the Supreme Lord is the first incarnation and plenary portion of the Supersoul. He is the Self of an unlimited number of living entities, and in Him rests the aggregate creation, which thus flourishes.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Lord expands Himself in two ways, by personal plenary expansions and separated minute expansions. The personal plenary expansions are visnu-tattvas, and the separated expansions are living entities. Since the living entities are very small, they are sometimes described as the marginal energy of the Lord. But the mystic yogis consider the living entities and the Supersoul, Paramatma, to be one and the same. It is, however, a minor point of controversy; after all, everything created rests on the gigantic virat or universal form of the Lord.