SB 10.8.7
sri-garga uvaca
yadunam aham acaryah
khyatas ca bhuvi sarvada
sutam maya samskrtam te
manyate devaki-sutam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Garga Muni said: My dear Nanda Maharaja, I am the priestly guide of the Yadu dynasty. This is known everywhere. Therefore, if I perform the purificatory process for your sons, Kamsa will consider Them the sons of Devaki.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Garga Muni indirectly disclosed that Krsna was the son of Devaki, not of Yasoda. Since Kamsa was already searching for Krsna, if the purificatory process were undertaken by Garga Muni, Kamsa might be informed, and that would create a catastrophe. It may be argued that although Garga Muni was the priest of the Yadu dynasty, Nanda Maharaja also belonged to that dynasty. Nanda Maharaja, however, was not acting as a ksatriya. Therefore Garga Muni said, “If I act as your priest, this will confirm that Krsna is the son of Devaki.”