CC Antya 18.32

yamunāte jala-keli gopī-gaṇa-saṅge
kṛṣṇa karena — mahāprabhu magna sei raṅge
Word for word: 
yamunāte — in the river Yamunā; jala-keli — pastimes in the water; gopī-gaṇa-saṅge — with the gopīs; kṛṣṇa karena — Kṛṣṇa performs; mahāprabhu — Śrī Caitanya Mahāprabhu; magna — fully merged; sei raṅge — in those pastimes.
Translation: 
Śrī Caitanya Mahāprabhu fully merged in the pastimes Lord Kṛṣṇa performed with the gopīs in the waters of the Yamunā.