Chapter 18 · Liberation through Renunciation · Krishna said
Bhagavad Gita 18.44 — Work of vaishya and shudra
कृषिगौरक्ष्यवाणिज्यं वैश्यकर्म स्वभावजम्। परिचर्यात्मकं कर्म शूद्रस्यापि स्वभावजम् ॥
kṛṣigaurakṣyavāṇijyaṃ vaiśyakarma svabhāvajam | paricaryātmakaṃ karma śūdrasyāpi svabhāvajam ||
Meaning
Farming, caring for cows and trade are the natural work of a vaishya; work of service is the natural work of a shudra.