Leviticus 25:39-43

39“‘If your brother becomes impoverished with regard to you so that he sells himself to you, you must not subject him to slave service.

40He must be with you as a hired worker, as a resident foreigner; he must serve with you until the year of jubilee,

41but then he may go free, he and his children with him, and may return to his family and to the property of his ancestors.

42Since they are my servants whom I brought out from the land of Egypt, they must not be sold in a slave sale.

43You must not rule over him harshly, but you must fear your God.