Leviticus 25:42 in the King James Version
For they are my servants, which I brought forth out of the land of Egypt: they shall not be sold as bondmen.
Context
41 Then he shall go out from you, he and his children with him, and shall return to his own family, and to the possession of his fathers.
42 For they are my servants, whom I brought out of the land of Egypt. They shall not be sold as slaves.
43 You shall not rule over him with harshness, but shall fear your God.