CC Madhya 23.48

vibhāva, anubhāva, sāttvika, vyabhicārī
sthāyi-bhāva ‘rasa’ haya ei cāri mili’
Word for word: 
vibhāva — special ecstasy; anubhāva — subordinate ecstasy; sāttvika — natural ecstasy; vyabhicārī — transitory ecstasy; sthāyi-bhāva — permanent ecstasy; rasa — mellow; haya — becomes; ei cāri — these four; mili’ — meeting.
Translation: 
“Permanent ecstasy becomes a more and more relishable transcendental mellow through the mixture of special ecstasy, subordinate ecstasy, natural ecstasy and transitory ecstasy.