Mahabharata Anushasna Parva Chapter 37:2

Mahabharata Anushasna Parva (Dana Dharma Parva) Chapter 37:2 Such a person deserves honours. Whether the person be one who is well-known and familiar, or one who has come newly, whether he has not been seen before, if he happens to possess these qualifications, he should be regarded as worthy of honours and hospitality. He who denies the authority of the Vedas, or strives to show that the scriptures should be disregarded, or approves of all breaches of restraint in society,—simply brings about his own ruin (and should not be regarded as worthy of gifts). That Brahmana who is vain of his learning, who speaks ill of the Vedas or who is devoted to the science of useless disputation, or who is desirous of gaining victory (in disputations) in assemblies of good men by disproving the reasons that exist for morality and religion and ascribing everything to chance, or who indulges in censuring and reproaching others or who reproves Brahmanas, or who is suspicious of all persons, or who is foolish and bereft of judgment, or who is bitter of speech, should be known to be as hateful as a dog. As a dog encounters others, barking the while and seeking to bite, such a person is even so, for he spends his breath in vain and seeks to destroy the authority of all the scriptures. Those practices that support society, the duties of righteousness, and all those acts which are productive of benefit to one's own self, should be attended to. A person that lives, attending to these, grows in prosperity for everlasting time. By paying off the debt one owes to the deities by performing sacrifices, that to the Rishis by studying the Vedas, that to the Pitris by procreating children, that to the Brahmanas by making presents unto them and that to guests by feeding them, in due order, and with purity of intention, and properly attending to the ordinances of the scriptures, a householder does not fall away from righteousness.