Bhagavatapurana 1.18.3

1.18.3

utsṛjya sarvataḥ saṅgaṃ vijñātājitasaṃsthitiḥ /
vaiyāsakerjahau śiṣyo gaṅgāyāṃ svaṃ kalevaram //

3. He severed himself from attachment to all things, and, having become the pupil of Sri Vyasa's son and derived from him the true knowledge of God (the independent and Supreme Lord of all), cast off his body into Ganga.