Markandeyapurana 28.2

Alarka spoke:
“Thou hast expounded, gracious lady, this the duty relating to the system of kingly government. I wish to hear that duty which concerns the four classes and the four periods of a brāhman’s life.”

Madālasā spoke:
“A brāhman’s duty is held to be threefold—liberality, study, sacrifice. There is no other fourth duty. His duty is regardless of his position. Irreproachable sacrificial and educational occupations, and the acceptance of gifts from the purified —this is fitly proclaimed his threefold means of livelihood, Liberality, study, sacrifice—this is declared to be the threefold duty of a kṣatriya also: protection of the earth, and subsistence by weapons are his means of livelihood. Liberality study, sacrifice,—that indeed is the threefold duty of a vaiśya also: merchandise, and the tending of cattle, and agriculture are his means of livelihood. Liberality, and sacrifice, obedience to dvijas, I have declared to he the threefold duty of the śūdra also; and his means of livelihood are a handicraft, obedience likewise to dvijas, nourishing them, buying and selling. These are said to he the duties of the four classes.