prag ayam vasudevasya
kvacij jatas tavatmajah
vasudeva iti sriman
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
For many reasons, this beautiful son of yours sometimes appeared previously as the son of Vasudeva. Therefore, those who are learned sometimes call this child Vasudeva.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Garga Muni indirectly disclosed, “This child was originally born as the son of Vasudeva, although He is acting as your child. Generally He is your child, but sometimes He is the son of Vasudeva.”