Srimad Bhagavatam Canto 07, Chapter 15, Text 63

SB 7.15.63

karya-karana-vastv-aikya-
 darsanam pata-tantuvat
avastutvad vikalpasya
 bhavadvaitam tad ucyate
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
When one understands that result and cause are one and that duality is ultimately unreal, like the idea that the threads of a cloth are different from the cloth itself, one reaches the conception of oneness called bhavadvaita.
Srimad Bhagavatam Canto 07, Chapter 15, Text 62
Srimad Bhagavatam Canto 07, Chapter 15, Text 64