Leviticus 25:46, 53
Leviticus 25:46 NIV
You 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.
Leviticus 25:53 NIV
They are to be treated as workers hired from year to year; you must see to it that those to whom they owe service do not rule over them ruthlessly.