Leviticus 25:44-46
Young's Literal Translation (YLT)
44`And thy man-servant and thy handmaid whom thou hast [are] of the nations who [are] round about you; of them ye buy man-servant and handmaid,
45and also of the sons of the settlers who are sojourning with you, of them ye buy, and of their families who [are] with you, which they have begotten in your land, and they have been to you for a possession;
46and ye have taken them for inheritance to your sons after you, to occupy [for] a possession;
to the age ye lay service upon them, but upon your brethren, the sons of Israel, one with another, thou dost not rule over him with rigour.