Garudapurana 2.40.26

2.40.26

ṛcā vai dāpayedarghyamekoddiṣṭe pṛthakpṛthak /
āpodevīrmadhumatīrādipīṭhe prakalpitam //

He should offer the water-offering with a verse separately in the rite for a single ancestor: / with ‘āpo devīr madhumatīḥ’ arranged on the first seat;