Mahabharata Santi Parva (Rajadharmanusasana Parva) Chapter 60:2
Establishing all his subjects in the observance of their respective duties, a king should cause all of them to do everything according to the dictates of righteousness. Whether he does or does not do any other act, if only he protects his subjects, he is regarded to accomplish all religious acts and is called a Kshatriya and the foremost of men. I shall now tell thee, O Yudhishthira, what the eternal duties of the Vaisya are. A Vaisya should make gifts, study the Vedas, perform sacrifices, and acquire wealth by fair means. With proper attention he should also protect and rear all (domestic) animals as a sire protecting his sons. Anything else that he will do will be regarded as improper for him. By protecting the (domestic) animals, he would obtain great happiness.
The Creator, having created the (domestic) animals, bestowed their care upon the Vaisya. Upon the Brahmana and the Kshatriya he conferred (the care of) all creatures. I shall tell thee what the Vaisya's profession is and how he is to earn the means of his sustenance. If he keeps (for others) six kine, he may take the milk of one cow as his remuneration; and if he keeps (for others) a hundred kine, he may take a single pair as such fee. If he trades with other's wealth, he may take a seventh part of the profits (as his share). A seventh also is his share in the profits arising from the trade in horns, but he should take a sixteenth if the trade be in hoofs. If he engages in cultivation with seeds supplied by others, he may take a seventh part of the yield. This should be his annual remuneration. A Vaisya should never desire that he should not tend cattle. If a Vaisya desires to tend cattle, no one else should be employed in that task. I should tell thee, O Bharata, what the duties of a Sudra are. The Creator intended the Sudra to become the servant of the other three orders. For this, the service of the three other classes is the duty of Sudra. By such service of the other three, a Sudra may obtain great happiness.
He should wait upon the three other classes according to their order of seniority. A Sudra should never amass wealth, lest, by his wealth, he makes the members of the three superior classes obedient to him. By this he would incur sin. With the king's permission, however, a Sudra, for performing religious acts, may earn wealth. I shall now tell thee the profession he should follow and the means by which he may earn his livelihood. It is said that Sudras should certainly be maintained by the (three) other orders. Worn-out umbrellas, turbans, beds and seats, shoes, and fans, should be given to the Sudra servants. Torn clothes which are no longer fit for wear, should be given away by the regenerate classes unto the Sudra. These are the latter's lawful acquisitions. Men conversant with morality say that if the Sudra approaches any one belonging to the three regenerate orders from desire of doing menial service, the latter should assign him proper work. Unto the sonless Sudra his master should offer the funeral cake.
The weak and the old amongst them should be maintainedThe Sudra should never abandon his master, whatever the nature or degree of the distress into which the latter may fall. If the master loses his wealth, he should with excessive zeal be supported by the Sudra servant. A Sudra cannot have any wealth that is his own. Whatever he possesses belongs lawfully to his master.