Srimad Bhagavatam Canto 12, Chapter 06, Text 45

SB 12.6.45

putran adhyapayat tams tu
 brahmarsin brahma-kovidan
te tu dharmopadestarah
 sva-putrebhyah samadisan
 
Translation: 
 
Brahma taught these Vedas to his sons, who were great sages among the brahmanas and experts in the art of Vedic recitation. They in turn took the role of acaryas and imparted the Vedas to their own sons.
Srimad Bhagavatam Canto 12, Chapter 06, Text 44
Srimad Bhagavatam Canto 12, Chapter 06, Text 46