Bhagavatapurana 1.1.15

1.1.15

yatpādasaṃśrayāḥ sūta munayaḥ praśamāyanāḥ /
sadyaḥ punantyupaspṛṣṭāḥ svardhunyāpo 'nusevayā //

15. The sages who, by devoutly clinging to His feet, have attained tranquillity, instantly purify those men that worship them, whereas the waters of the Ganges purify men only by long continued use.