Mbh 12.294.1a

"'"Parasara said, 'The lowest order, it is proper, should derive their sustenance from the three other orders. Such service, rendered with affection and reverence, makes them righteous.[1522] If the ancestors of any Sudra were not engaged in service, he should not still engage himself in any other occupation (than service). Truly, he should apply himself to service as his occupation. In my opinion, it is proper for them to associate, under all circumstances, with good men devoted to righteousness, but never with those that are wicked. As in the Eastern hills, jewels and metals blaze with greater splendour in consequence of their adjacence to the Sun, even so the lowest order blazes with splendour in consequence of their association with the good. A piece of white cloth assumes that hue with which it is dyed. Even such is the case with Sudras.[1523] Hence also, one should attach oneself to all good qualities but never to qualities that are evil. The life of human beings in this world is fleeting and transitory. That wise man who, in happiness as also in misery, achieves only what is good, is regarded as a true observer of the scriptures. That man who is endued with intelligence would never do an act which is dissociated from virtue, however high may the advantages be of that act. Indeed, such an act is not regarded as truly beneficial. That lawless king who, snatching thousands of kine from their lawful owners, gives them away (unto deserving persons), acquires no fruit (from that act of giving) beyond an empty sound (expressive of the act he does). On the other hand, he incurs the sin of theft. The Self-born at first created the Being called Dhatri held in universal respect. Dhatri created a son who was engaged in upholding all the worlds.[1524] Worshipping that deity, the Vaisya employs himself, for the means of his support, in agriculture and the rearing of cattle. The Kshatriyas should employ themselves in the task of protecting all the other classes.