Brahmanas, ksatriyas, vaisyas and sudras are distinguished by the qualities born of their own natures in accordance with the material modes
Appearance
Bhagavad-gita As It Is
BG Chapters 13 - 18
Brāhmaṇas, kṣatriyas, vaiśyas and śūdras are distinguished by the qualities born of their own natures in accordance with the material modes.
BG 18.41, Purport: Brāhmaṇas, kṣatriyas, vaiśyas and śūdras are distinguished by the qualities born of their own natures in accordance with the material modes, O chastiser of the enemy."