Padma Purana 5.117.84

Padmapurāṇa 5.117.84

udīratāmititathāpitṛpātrasthalekṣipet
gāyatryācākṣatajalaṃdevapātrasthalekṣipet
pākajātaṃtathā'bhyukṣyamantrametadudīrayet