Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 7

Sanskrit:

त्वमेक: सर्वभूतानां जन्मकृद् वृत्तिद: पिता ।तथापि न: प्रजानां ते शुश्रूषा केन वा भवेत् ॥ ७ ॥

ITRANS:

tvam ekaḥ sarva-bhūtānāṁjanma-kṛd vṛttidaḥ pitātathāpi naḥ prajānāṁ teśuśrūṣā kena vā bhavet

Translation:

You are the father of all living entities and the source of their subsistence because they are all born of you. Please order us how we may be able to render service unto you.

Purport:

A son’s duty is not only to make the father the source of supply for all his needs, but also, when he is grown up, to render service unto him. That is the law of creation beginning from the time of Brahmā. A father’s duty is to bring up the son until he is grown, and when the son is grown up, it is his duty to render service unto the father.