Mbh 12.60.2a

"'Bhishma said, "I bow down to Dharma who is great, and to Krishna who is Brahma. Having bowed down also unto the Brahmanas (assembled here), I shall discourse on duties that are eternal. The suppression of wrath, truthfulness of speech, justice, forgiveness, begetting children upon one's own wedded wives, purity of conduct, avoidance of quarrel, simplicity, and maintenance of dependants, these nine duties belong to all the four orders (equally). Those duties, however, which belong exclusively to Brahmanas, I shall now tell thee. Self-restraint, O king, has been declared to be the first duty of Brahmanas. Study of the Vedas, and patience in undergoing austerities, (are also their other duties). By practising these two, all their acts are accomplished. If while engaged in the observance of his own duties, without doing any improper act, wealth comes to a peaceful Brahmana possessed of knowledge, he should then marry and seek to beget children and should also practise charity and perform sacrifices. It has been declared by the wise that wealth thus obtained should be enjoyed by distributing it (among deserving persons and relatives). By his study of the Vedas all the pious acts (laid down for the Brahmana) are accomplished. Whether he does or does not achieve anything else, if he devotes himself to the study of the Vedas, he becomes (by that) known as a Brahmana or the friend of all creatures. I shall also tell thee, O Bharata, what the duties are of a Kshatriya. A Kshatriya, O king, should give but not beg, should himself perform sacrifices but not officiate as a priest in the sacrifices of others. He should never teach (the Vedas) but study (them with a Brahmana preceptor). He should protect the people. Always exerting himself for the destruction of robbers and wicked people, he should put forth his prowess in battle.