Bhagwad Gita
Chapter 18, Verse 44
कृषिगौरक्ष्यवाणिज्यं वैश्यकर्म स्वभावजम्।परिचर्यात्मकं कर्म शूद्रस्यापि स्वभावजम्।।18.44।।
Farming, cattle raising and business are the qualities of work for the vaisyas, and for the sudras there is labor and service to others.