eta bali' ānila tāṅre gaṅgā-sannidhāne
āveśe prabhura haila gaṅgāre yamunā-jñāne
eta bali'-saying this; ānila—He brought; tāṅre—Him; gaṅgā-sannidhāne—near the Ganges; āveśe—in ecstasy; prabhura—of the Lord; haila—there was; gaṅgāre—of the river Ganges; yamunā-jñāne—acceptance as the river Yamunā.
Saying this, Nityānanda Prabhu took Caitanya Mahāprabhu near the Ganges, and the Lord, in His ecstasy, accepted the river Ganges as the river Yamunā.
Link to this page: https://prabhupadabooks.com/cc/madhya/3/26