Vishnupurana 3.8.22

3.8.22

dānaṃ dadyād yajed devān yajñaiḥ svādhyāyatatparaḥ
nityodakī bhaved vipraḥ kuryāc cāgniparigraham //

Aurva having thus spoken, Sagara said to him, "Tell me then, venerable Brahman, what are the duties of caste and condition: I am desirous of knowing them." To which Aurva answered and said, "Attentively listen to the duties which I shall describe as those severally of the Brahman, the Kshatriya, the Vaiśya, and the Śúdra. The Brahman should make gifts, should worship the gods with sacrifices, should be assiduous in studying the Vedas, should perform ablutions and libations with water, and should preserve the sacred flame. For the sake of subsistence he may offer sacrifices on behalf of others, and may instruct them in the Śástras; and he may accept presents of a liberal description in a becoming manner (or from respectable persons, and at an appropriate season). He must ever seek to promote the good of others, and do evil unto none; for the best riches of a Brahman are universal benevolence. He should look upon the jewels of another person as if they were pebbles; and should, at proper periods, procreate offspring by his wife. These are the duties of a Brahman.