Vishnupurana 3.9.1

3.9.1

aurva uvāca:
bālaḥ kṛtopanayano vedāharaṇatatparaḥ
gurugehe vased bhūpa brahmacārī samāhitaḥ //

AURVA continued.--"When the youth has been invested with the thread of his caste, let him diligently prosecute the study of the Vedas, in the house of his preceptor, with an attentive spirit, and leading a life of continence. He is to wait upon his Guru, assiduously observant of purificatory practices, and the Veda is to be acquired by him, whilst he is regular in the performance of religious rites. In the morning Sandhya he is first to salute the sun; in the evening, fire; and then to address his preceptor with respect. He must stand when his master is standing; move when he is walking; and sit beneath him when he is seated: he must never sit, nor walk, nor stand when his teacher does the reverse. When desired by him, let him read the Veda attentively, placed before his preceptor; and let him eat the food he has collected as alms, when permitted by his teacher. Let him bathe in water which has first been used for his preceptor's ablutions; and every morning bring fuel and water, and whatsoever else may be required.