Mbh 13.90.3a

"'"I shall now, O chief of Bharata's race, tell thee who are sanctifiers of the line. Do thou find them out by examination. All those Brahmanas that are cleansed by knowledge, Vedic study, and vows and observances, and they that are of good and righteous behaviour, should be known as sanctifiers of everything. I shall now tell thee who deserve to sit in the line. Thou shouldst know them to be such whom I shall indicate presently. He that is conversant with the three Nachiketas, he that has set up the five sacrificial fires, he that knows the five Suparnas, he that is conversant with the six branches (called Angas) of the Veda, he that is a descendant of sires who were engaged in teaching the Vedas and is himself engaged in teaching, he that is well-conversant with the Chhandas, he that is acquainted with the Jeshtha Saman, he that is obedient to the sway of his parents, he that is conversant with the Vedas and whose ancestors have been so for ten generations, he that has congress with only his wedded wives and this at their seasons, and he who has been cleansed by knowledge, by the Veda, and by vows and observances,--even such a Brahmana,--sanctifies the line. He who reads the Atharva-siras, who is devoted to the observance of Brahmacharya practices, and who is steady in observance of righteous vows, who is truthful and of righteous conduct, and who is duly observant of the duties laid down for his order, they also that have undergone fatigue and labour for bathing in the waters of tirthas, that have undergone the final bath after performing sacrifices with proper Mantras that are freed from the sway of wrath, that are not restless, that are endued with forgiving dispositions, that are self-restrained masters of their senses, and they are devoted to the good of all creatures,--these should be invited to Sraddhas. Anything given to these becomes inexhaustible. These indeed, are sanctifiers of lines.