SB 5.20.22
yasam ambhah pavitram amalam upayuñjanah purusa-rsabha-dravina-devaka-samjña varsa-purusa
apomayam devam apam purnenañjalina yajante.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The inhabitants of Krauñcadvipa are divided into four castes, called the Purusas, Rsabhas, Dravinas and Devakas. Using the waters of those sanctified rivers, they worship the Supreme Personality of Godhead by offering a palmful of water at the lotus feet of Varuna, the demigod who has a form of water.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Visvanatha Cakravarti Thakura says, apomayah asmayam: with joined palms the inhabitants of the various sections of Krauñcadvipa offer the sanctified waters of the rivers to a deity made of stone or iron.