Mahabharata Santi Parva Chapter 37:4

Mahabharata Santi Parva (Rajadharmanusasana Parva) Chapter 37:4 One may, from compassion, give unto a person that is poor or afflicted or ill. But he should not give unto such a person in the belief that he would derive any (spiritual) benefit from it or that he would earn any religious merit by it. There is no doubt that a gift made to Brahmana bereft of the Vedas becomes perfectly fruitless in consequence of the fault of the recipient. As an elephant made of wood or an antelope made of leather, even so is a Brahmana that has not studied the Vedas. All the three have nothing but namesAs a eunuch is unproductive with women, as a cow is unproductive with a cow, as a bird lives in vain that is featherless, even so is a Brahmana that is without mantras. As grain without kernel, as a well without water, as libations poured on ashes, even so is a gift to a Brahmana void of learning. An unlearned Brahmana is an enemy (to all) and is the destroyer of the food that is presented to the gods and Pitris. A gift made to such a person goes for nothing. He is, therefore, like unto a robber (of other people's wealth). He can never succeed in acquiring regions of bliss hereafter.' I have now told thee in brief, O Yudhishthira, all that was said (by Manu on that occasion). This high discourse should be listened to by all, O bull of Bharata's race.