RigVeda One of the four Vedas - Very Old Sacred Hindu Text
Rigveda: Purusha Sukta cast divide …When they divided the Man, into how many parts did they apportion him? What do they call his mouth, his two arms and thighs and feet? His mouth became the Brahmin; his arms were made into the Kshatriya [warrior], his thighs the Vaishya [merchants], and from his feet the Shudras [servants] were born.