Leviticus

If thou buy an Hebrew servant, six years he shall serve: and in the seventh he shall go out free for nothing.

If he came in by himself, he shall go out by himself: if he were married, then his wife shall go out with him.

Then his master shall bring him unto the judges; he shall also bring him to the door, or unto the door post; and his master shall bore his ear through with an aul; and he shall serve him for ever.

And he shall reckon with him that bought him from the year that he was sold to him unto the year of jubile: and the price of his sale shall be according unto the number of years, according to the time of an hired servant shall it be with him.

And if he be not redeemed in these years, then he shall go out in the year of jubile, both he, and his children with him.