Leviticus 25:40-42

⁴⁰As a hired servant, and as a temporary resident, he shall be with you; he shall serve with you until the Year of Jubilee.

⁴¹Then 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.

⁴²For they are my servants, whom I brought out of the land of Egypt. They shall not be sold as slaves.