CC Madhya 20.188

vaibhava-prakāśe āra prābhava-vilāse
eka-i mūrtye baladeva bhāva-bhede bhāse
Word for word: 
vaibhava-prakāśe — in vaibhava manifestation; āra — and; prābhava-vilāse — in the prābhava pastime form; eka-i mūrtye — in one form; baladeva — Lord Baladeva; bhāva-bhede — according to different emotions; bhāse — exists.
Translation: 
“Śrī Balarāma is a vaibhava-prakāśa manifestation of Kṛṣṇa. He is also manifested in the original quadruple expansions of Vāsudeva, Saṅkarṣaṇa, Pradyumna and Aniruddha. These are prābhava-vilāsa expansions with different emotions.