Chandogya Upanishad 8.15.1

8.15.1

tad dhaitad brahmā prajāpataya uvāca prajāpatir manave manuḥ prajābhyaḥ \
ācāryakulād vedam adhītya yathāvidhānaṃ guroḥ (S ) kuṭumbe (S ) śucau deśe svādhyāyam adhīyāno dharmikān vidadhad ātmani sarvendriyāṇi saṃpratiṣṭhāpyāhiṃsan sarvabhūtāny anyatra tīrthebhyaḥ \
sa khalv evaṃ vartayan yāvad āyuṣaṃ brahmalokam abhisaṃpadyate \
na ca punar āvartate na ca punar āvartate \\815.1\

Brahmā expounded this to Prajāpati, Prajāpati to Manu and Manu to his descendants. He who has read the Veda according to the prescribed rule, in the time left over after performing his duties to the teacher, he who after having come back from the teacher's house, settles down in his household, continues the study of the Veda in a clean place, and has virtuous sons and disciples, he who withdraws all his senses into the Ātman, who practises non-injury to all beings except in places specially ordained, he who behaves thus throughout his life reaches the world of Brahman and does not return again—yea, he does not return again.