Srimad Bhagavatam Canto 10, Chapter 47, Text 25

SB 10.47.25

bhagavaty uttamah-sloke
 bhavatibhir anuttama
bhaktih pravartita distya
 muninam api durlabha
 
Translation: 
 
By your great fortune you have established an unexcelled standard of pure devotion for the Lord, Uttamahsloka — a standard even the sages can hardly attain.
 
Purport: 
 
The term pravartita indicates that the gopis brought to this world a standard of pure love of God that was previously unknown on the earth. Thus Uddhava congratulates them on their unparalleled contribution to the religious life.
Srimad Bhagavatam Canto 10, Chapter 47, Text 24
Srimad Bhagavatam Canto 10, Chapter 47, Text 26