CC Madhya 8.140
“ ‘When Kṛṣṇa left the rāsa-līlā dance, the gopīs became very morose, and when they were grieving, Kṛṣṇa reappeared dressed in yellow garments. Wearing a flower garland and smiling, He was attractive even to Cupid. In this way Kṛṣṇa appeared among the gopīs.’
This verse is from Śrīmad-Bhāgavatam (10.32.2).