Śrīmad-Bhāgavatam · Text 10.16.6
Who is speaking and story frame
तं चण्डवेगविषवीर्यमवेक्ष्य तेन
दुष्टां नदीं च खलसंयमनावतार: ।
कृष्ण: कदम्बमधिरुह्य ततोऽतितुङ्ग-
मास्फोट्य गाढरशनो न्यपतद् विषोदे ॥ ६ ॥
taṁ caṇḍa-vega-viṣa-vīryam avekṣya tena
duṣṭāṁ nadīṁ ca khala-saṁyamanāvatāraḥ
kṛṣṇaḥ kadambam adhiruhya tato ’ti-tuṅgam
āsphoṭya gāḍha-raśano nyapatad viṣode
Lord Kṛṣṇa saw how the Kāliya serpent had polluted the Yamunā River with his terribly powerful poison. Since Kṛṣṇa had descended from the spiritual world specifically to subdue envious demons, the Lord immediately climbed to the top of a very high kadamba tree and prepared Himself for battle. He tightened His belt, slapped His arms and then jumped into the poisonous water.
Read the purport on Vedabase.ioFrom Canto 10, chapter 14 onward, the translation and purports were completed by Śrīla Prabhupāda's disciples after his departure, and published by the Bhaktivedanta Book Trust.