Srimad Bhagavatam
Canto 10 Chapter 16 Text 1

sri-suka uvaca
vilokya dusitam krsnam
krsnah krsnahina vibhuh
tasya visuddhim anvicchan
sarpam tam udavasayat

TRANSLATION
Sukadeva Gosvami said: Lord Sri Krsna, the Supreme Personality of Godhead, seeing that the Yamuna River had been contaminated by the black snake Kaliya, desired to purify the river, and thus the Lord banished him from it.