Deuteronomy 15:12
"When a fellow Hebrew male or female slave is sold to you and serves you for six years, then in the seventh year you are to set them free.
Jeremiah 34:14
"At the end of seven years, each of you is to set free your fellow Hebrew who has sold himself to you and has served you for six years. You are to send him out from you with no further obligation." But your ancestors didn't obey me or pay attention.
Leviticus 25:39-41
"If your brother with you becomes so poor that he sells himself to you, you are not to make him serve like a bond slave.
Exodus 21:2-6
"When you acquire a Hebrew servant, he is to serve for six years, and in the seventh he is to go out a free man without paying anything.
Deuteronomy 15:1
"You must cancel your debts at the end of every seventh year.
John 8:35-36
The slave does not remain in the household forever, but the son does remain forever.