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.