Gargamuni indirectly disclosed that Kamsa was the son of Devak not of Yashoda Since Kansa was already searching for Krishna, if the purificatory process were undertaken by Gargamuni, Kansa might be informed, and that would create a catastrophe. It may be argued that although Gargamuni was the priest of the Yadu dynasty, Nanda Maharaja also belonged to that dynasty. Nanda Maharaja, however, was not acting as a kshtariya. Therefore Gargamuni said, “If I act as your priest, this will confirm that Krisna is the son of Devaki”
This is very good example for all of us. It is explained in the Srimad Bhagavatam that when one performs devotional service in material life karma yoga means to work without being attached to the fruit. But in spiritual life it is said in Bhagvatam that when you perform devotional service certain benefits, certain fruits will come from that action of devotional service you should not be attached to that, you should understand it is for Krishna’s enjoyment.