yam ahur adyam purusam
yatra visva ime lokah
sa-vikasam ta asate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The purusa incarnation lying on the Causal Ocean is called the original purusa in the material creations, and in His virat form, in whom all the planets and their inhabitants live, He has many thousands of legs and hands.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The first purusa is Karanodakasayi Visnu, the second purusa is Garbhodakasayi Visnu, and the third purusa is Ksirodakasayi Visnu, in whom is contemplated the virat-purusa, the gigantic form in which all the planets with their different developments and inhabitants are floating.