Genesis 9:22-27 [9:22] And Ham, the father of Canaan , saw the nakedness of his father, and told his two brethren without. [9:23] And Shem and Japheth took a garment, and laid it upon both their shoulders, and went backward, and covered the nakedness of their father; and their faces were backward, and they saw not their father's nakedness. [9:24] And Noah awoke from his wine, and knew what his younger son had done unto him. [9:25] And he said, Cursed be Canaan ; a servant of servants shall he be unto his brethren. 9:26 And he said, Blessed be the LORD God of Shem; and Canaan shall be his servant . [9:27] God shall enlarge Japheth, and he shall dwell in the tents of Shem; and Canaan shall be his servant.
Exodus 21:2 If thou buy an Hebrew servant, six years he shall serve: and in the seventh he shall go out free for nothing.