Leviticus 25:39-46

39“ ‘If any of your fellow Israelites become poor and sell themselves to you, do not make them work as slaves. 40They are to be treated as hired workers or temporary residents among you; they are to work for you until the Year of Jubilee. 41Then they and their children are to be released, and they will go back to their own clans and to the property of their ancestors. 42Because the Israelites are my servants, whom I brought out of Egypt, they must not be sold as slaves. 43Do not rule over them ruthlessly, but fear your God. 44“ ‘Your male and female slaves are to come from the nations around you; from them you may buy slaves. 45You may also buy some of the temporary residents living among you and members of their clans born in your country, and they will become your property. 46You can bequeath them to your children as inherited property and can make them slaves for life, but you must not rule over your fellow Israelites ruthlessly.