putrāṇām - of sons; hi - indeed; paraḥ - superior; dharmaḥ - religious principle; pitṛ-śuśrūṣaṇam - the service of the parents; satām - good; api - even; putra-vatām - of those who have sons; brahman - O dear brāhmaṇa; kim uta - what to speak; brahmacāriṇām - of brahmacārīs.

O brāhmaṇa, the highest duty of a son, even though he has sons of his own, is to serve his parents, and what to speak of a son who is a brahmacārī?