Bhagavad-gītā 18.44

kṛṣiplowing — plowing; goof cows — of cows; rakṣyaprotection — protection; vāṇijyamtrade — trade; vaiśyaof a vaiśya — of a vaiśya; karmaduty — duty; svabhāvaborn of his own nature-jamborn of his own nature — born of his own nature; paricaryāservice — service; ātmakamconsisting of — consisting of; karmaduty — duty; śūdrasyaof the śūdra — of the śūdra; apialso — also; svabhāvaborn of his own nature-jamborn of his own nature — born of his own nature.