The Great Epic of the Bhārata dynasty 13.90.28

13.90.28

upapanno gurukule satyavādī sahasradaḥ |
agryaḥ sarveṣu vedeṣu sarvapravacaneṣu ca || 28 ||

They that are conversant with Bhashyas, they also that are devoted to grammatical studies, they that study the Puranas and they that study the Dharmasastras and having studied them (i.e., the Puranas and Dharmasastras) act up to the standard laid down in them, he that has lived (for the stated period) in the abode of his preceptor, he that is truthful in speech, he that is a giver of thousands, they that are foremost in (their knowledge of) all the Vedas and the scriptural and philosophical aphorisms,--these sanctify the line as far they look at it. And because they sanctify all who sit in the line, therefore are they called sanctifiers of lines. Utterers of Brahma say that even a single person that happens to be the descendant of sires who were teachers of the Veda and that is himself a Vedic teacher, sanctifies full seven miles around him. If he that is not a Ritwik and that is not a Vedic teacher takes the foremost seat in a Sraddha, with even the permission of the other Ritwiks there present, he is said to take (by that act of his) the sins of all who may be sitting in the line. If, on the other hand, he happens to be conversant with the Vedas and freed from all those faults that are regarded as capable of polluting the line, he shall not, O king, be regarded as fallen (by taking the foremost seat in a Sraddha). Such a man would then be really a sanctifier of the line.