CC Antya 7.43

sarvottama bhajana ei sarva-bhakti jini’
ataeva kṛṣṇa kahe, — ‘āmi tomāra ṛṇī’
Synonyms: 
sarva-uttama — above all; bhajana — devotional service; ei — this; sarva-bhakti — all types of bhakti; jini’ — conquering; ataeva — therefore; kṛṣṇa kahe — Lord Kṛṣṇa says; āmi — I; tomāra — your; ṛṇī — debtor.
Translation: 
“The conjugal love of the gopīs is the most exalted devotional service, surpassing all other methods of bhakti. Therefore Lord Kṛṣṇa is obliged to say, ‘My dear gopīs, I cannot repay you. Indeed, I am always indebted to you.’