Leviticus 25:39-43

39‘And if your fellow countryman becomes so poor [in his dealings] with you that he sells himself to you [as payment for a debt], you shall not let him do the work of a slave [who is ineligible for redemption],

40but he is to be with you as a hired man, as if he were a temporary resident; he shall serve with you until the Year of Jubilee,

41and then he shall leave you, he and his children with him, and shall go back to his own family and return to the property of his fathers.

42For the Israelites are My servants whom I brought out of the land of Egypt; they shall not be sold in a slave sale.

43You shall not rule over him with harshness (severity, oppression), but you are to fear your God [with profound reverence].