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 Dvāpara-yuga the Vedas are edited into separate divisions by eminent sages.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
ते परम्परया प्राप्तास्तत्तच्छिष्यैर्धृतव्रतैः । चतुर्युगेष्वथ व्यस्ता द्वापरादौ महर्षिभिः
te paramparayā prāptāstattacchiṣyairdhṛtavrataiḥ | caturyugeṣvatha vyastā dvāparādau maharṣibhiḥ
SB 12.6.46