Leviticus 25:44

25:44 “‘As for your male and female slaves who may belong to you – you may buy male and female slaves from the nations all around you.

Leviticus 25:46

25:46 You may give them as inheritance to your children after you to possess as property. You may enslave them perpetually. However, as for your brothers the Israelites, no man may rule over his brother harshly.