Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.2.4

1.4.2.4

parastādarvākpravṛṇīte | parastāddhyarvācyaḥ prajāḥ prajāyante jyāyasaspataya u caivaitaṃ nihnuta idaṃ hi pitaivāgre 'tha putro 'tha pautrastasmātparastādarvākpravṛṇīte

He calls from the remote end (of the sacrificer's ancestral line) downwards; for it is from the remote end downwards that a race is propagated. He (the Hotri) also thereby propitiates the lord of seniority for him (the Sacrificer); for here among men the father comes first, then the son, and then the grandson: this is the reason why he calls from the remote end downwards.