SB 3.8.29
parardhya-keyura-mani-praveka-
paryasta-dordanda-sahasra-sakham
avyakta-mulam bhuvananghripendram
ahindra-bhogair adhivita-valsam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As a sandalwood tree is decorated with fragrant flowers and branches, the Lord’s body was decorated with valuable jewels and pearls. He was the self-situated tree, the Lord of all others in the universe. And as a sandalwood tree is covered with many snakes, so the Lord’s body was also covered by the hoods of Ananta.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The word avyakta-mulam is significant here. Generally, no one can see the roots of a tree. But as far as the Lord is concerned, He is the root of Himself because there is no other separate cause of His standing but He Himself. In the Vedas it is said that the Lord is svasrayasraya: He is His own support, and there is no other support for Him. Therefore, avyakta means the Supreme Lord Himself and no one else.