Shiva Purana
पयः पृथिव्यामिति च पयसा स्नानमाचरेत् । दधिक्राव्णेतिमंत्रेण दधिस्नानं च कारयेत् 1-20-२० ।
The ceremonial ablution with milk shall be performed with the mantra “Payaḥ Pṛthivyām”[18] etc. The ceremonial ablution with curd shall be performed with the mantra “Dadhi Krāvṇaḥ[19]” etc.
english translation
payaH pRthivyAmiti ca payasA snAnamAcaret । dadhikrAvNetimaMtreNa dadhisnAnaM ca kArayet 1-20-20 ।
hk transliteration by Sanscript