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

Expressions researched:
"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"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

It may be argued that although Garga Muni was the priest of the Yadu dynasty, Nanda Mahārāja also belonged to that dynasty. Nanda Mahārāja, however, was not acting as a kṣatriya. Therefore Garga Muni said, "If I act as your priest, this will confirm that Kṛṣṇa is the son of Devakī.".

SB 10.8.7, Translation and Purport

Garga Muni said: My dear Nanda Mahārāja, I am the priestly guide of the Yadu dynasty. This is known everywhere. Therefore, if I perform the purificatory process for your sons, Kaṁsa will consider Them the sons of Devakī.

Garga Muni indirectly disclosed that Kṛṣṇa was the son of Devakī, not of Yaśodā. Since Kaṁsa was already searching for Kṛṣṇa, if the purificatory process were undertaken by Garga Muni, Kaṁsa 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 Mahārāja also belonged to that dynasty. Nanda Mahārāja, however, was not acting as a kṣatriya. Therefore Garga Muni said, "If I act as your priest, this will confirm that Kṛṣṇa is the son of Devakī."