Mbh 12.76.2a

"'Bhishma said, "Those Brahmanas, O king, that are possessed of learning and beneficent features, and that look upon all creatures with an equal eye, are said to be equal to Brahma. They that are conversant with the Riches, the Yajuses and the Samans, and who are devoted to the practices of their order, are, O king, equal to the very gods. Those, however, amongst them that are not well-born and not devoted to the duties of their order, and are besides wedded to evil practices, are like Sudras. A virtuous king should realise tribute from and impress without pay into the public service those Brahmanas that are not possessed of Vedic lore and that have not their own fires to worship. They that are employed in courts of justice for summoning people, they that perform worship for others for a fee, they that perform the sacrifices of Vaisyas and Sudras, they that officiate in sacrifices on behalf of a whole village, and they that make voyages on the ocean,--these five are regarded as Chandalas among Brahmanas.[232] They amongst them that become Ritwikas, Purohitas, counsellors, envoys, and messengers, become, O king, equal to Kshatriyas.[233] They amongst them that ride horses or elephants or cars or become foot-soldiers, become, O king, equal to Vaisyas. If the king's treasury is not full, he may realise tribute from these. In realising tribute, the king, however, should exclude those Brahmanas that are (for their conduct) equal to the gods or Brahma. The Vedas say that the king is the lord of the wealth belonging to all the orders except Brahmanas. He can take the wealth of those Brahmanas also that have fallen away from their legitimate duties. The king should never be indifferent towards those Brahmanas that are not observant of their duties. For the sake of making his people virtuous, he should punish and separate them from their superiors.