Vishnupurana 3.15.4

3.15.4

etān niyojayec chrāddhe pūrvoktān prathamaṃ nṛpa
brāhmaṇān pitṛpuṣṭyartham anukalpeṣv anantarān //

AURVA proceeded.--"Hear next, oh prince, what description of Brahman should be fed at ancestral ceremonies. he should be one studied in various triplets of the Rich and Yajur Vedas; one who is acquainted with the six supplementary sciences of the Vedas; one who understands the Vedas; one who practises the duties they enjoin; one who exercises penance; a chanter of the principal Sáma-veda, an officiating priest, a sister's son, a daughter's son, a son-in-law, a father-in-law, a maternal uncle, an ascetic, a Brahman who maintains the five fires, a pupil, a kinsman; one who reverences his parents. A man should first employ the Brahmans first specified in the principal obsequial rite; and the others (commencing with the ministering priest) in the subsidiary ceremonies instituted to gratify his ancestors.