Mbh 12.234.1a

"'"Vyasa said, 'Thou hadst asked me about the Creation of all beings; I have now narrated that to thee in full. Listen to me as I tell thee now what the duties are of a Brahmana. The rituals of all ceremonies for which sacrificial fees are enjoined, commencing with Jatakarma and ending with Samavartana, depend for their performance upon a preceptor competent in the Vedas.[894] Having studied all the Vedas and having displayed a submissive behaviour towards his preceptor during his residence with him, and having paid the preceptor's fee, the youth should return home with a thorough knowledge of all sacrifices.[895] Receiving the permission of his preceptor, he should adopt one of the four modes of life and live in it in due observance of its duties till he casts off his body. He should either lead a life of domesticity with spouses and engaged in creating offspring, or live in the observance of Brahmacharya; or in the forest in the company of his preceptor, or in the practice of the duties laid down for a yati. A life of domesticity is said to be the root of all the other modes of life. A self-restrained householder who has conquered all his attachments to worldly objects always attains to success (in respect of the great object of life). A Brahmana, by begetting children, by acquiring a knowledge of the Vedas, and by performing sacrifices, pays off the three debts he owes.[896] He should then enter the other modes of life, having cleansed himself by his acts. He should settle in that place which he may ascertain to be the most sacred spot on earth, and he should strive in all matters that lead to fame, for attaining to a position of eminence. The fame of Brahmanas increases through penances that are very austere, through mastery of the various branches of knowledge, through sacrifices, and through gifts. Indeed, a person enjoys endless regions of the righteous (in the next world) as long as his deeds or the memory thereof lasts in this world.