Srimad Bhagavatam Canto 12, Chapter 06, Text 46

SB 12.6.46

te paramparaya praptas
 tat-tac-chisyair dhrta-vrataih
catur-yugesv atha vyasta
 dvaparadau maharsibhih
 
Translation: 
 
In this way, throughout the cycles of four ages, generation after generation of disciples — all firmly fixed in their spiritual vows — have received these Vedas by disciplic succession. At the end of each Dvapara-yuga the Vedas are edited into separate divisions by eminent sages.
Srimad Bhagavatam Canto 12, Chapter 06, Text 45
Srimad Bhagavatam Canto 12, Chapter 06, Text 47