Mbh 13.90.3d

Such offerings gratify neither the gods nor the Pitris. Instead of reaching the other world, they wander about even here like a cow that has lost her calf wandering about within the fold. As those libations of ghee that are poured upon the extinguished ashes of a sacrificial fire never reach either the gods or the Pitris, after the same manner a gift that is made to a dancer or a singer or a Dakshina presented to a lying or deceitful person, produces no merit. The Dakshina that is presented to a lying or deceitful person destroys both the giver and the receiver without benefiting them in any respect. Such a Dakshina is destructive and highly censurable. The Pitris of the person making it have to fall down from the path of the deities. The gods know them to be Brahmanas who always tread, O Yudhishthira, within the bounds set up by the Rishis who are conversant with all duties, and who have a firm faith in their efficacy. Those Brahmanas that are devoted to Vedic study, to knowledge, to penances, and to acts, O Bharata, should be known as Rishis. The offerings made at Sraddhas should be given unto those that are devoted to knowledge. Verily, they are to be regarded as men who never speak ill of the Brahmanas. Those men should never be fed on occasions of Sraddhas who speak ill of Brahmanas in course of conversation in the midst of assemblies. If Brahmanas, O king, be calumniated, they would destroy three generations of the calumniator.[410] This is the declaration, O king, of the Vaikhanasa Rishis. Brahmanas conversant with the Vedas should be examined from a distance. Whether one likes them or feels a dislike for them, one should give unto such Brahmanas the offerings made at Sraddhas. That man who feeds thousands upon thousands of false Brahmanas acquires merit that is attainable by feeding even one Brahmana if the latter happens to be possessed of a knowledge of the Vedas, O Bharata!"'"