Farming, cattle-keeping and trade are the work of a Vaishya, born of their own nature. And work that consists of service is likewise the work of a Shudra, born of their own nature.
Explanation
Krishna is concluding his description of the four social orders (varṇa), which he links to the natural dispositions (svabhāva) shaped by the three guṇas, the strands of nature. After the Brahmin and Kshatriya duties, he names the Vaishya's work (agriculture, cattle-keeping, trade) and the Shudra's work (service, paricaryā). Traditional commentators often read these as occupations assigned by birth, while some modern readers stress that the verse speaks of work arising from one's own nature, not of worth.