Caitanya-caritāmṛta 4.160
atyanta-nigūḍha ei rasera siddhānta svarūpa-gosāñi mātra jānena ekānta
[atyanta-nigoodha ei rasera siddhaanta svaroopa-gosaani maatra jaanena ekaanta]
Blended reading (Sanskrit + English inline)
atyanta-nigūḍha ei rasera siddhānta svarūpa-gosāñi mātra jānena ekānta
This conclusion of rasa is extremely deep. Only Svarūpa Dāmodara knows much about it.
My note
Source: vedabase.io