śrī-śuka uvāca
kālindyāṁ kāliyasyāsīd
hradaḥ kaścid viṣāgninā
śrapyamāṇa-payā yasmin
patanty upari-gāḥ khagāḥ
śrī-śukaḥ uvāca - Śrī Śukadeva Gosvāmī said; kālindyām - within the river Yamunā; kāliyasya - of the serpent Kāliya; āsīt - there was; hradaḥ - lake; kaścit - a certain; viṣa - of his poison; agninā - by the fire; śrapyamāṇa - being heated and boiled; payāḥ - its water; yasmin - into which; patanti - would fall down; upari-gāḥ - traveling above; khagāḥ - the birds.
In this regard the ācāryas explain that the Kāliya lake was situated apart from the main current of the river; otherwise the Yamunā’s waters would have been poisonous even in cities like Mathurā and in other places farther away.