Leviticus 25:51

after he is sold he may be redeemed. One of his brothers may redeem him;

or his uncle, or his uncle’s son, may redeem him, or any who is a close relative to him of his family may redeem him; or if he has grown rich, he may redeem himself.

He shall reckon with him who bought him from the year that he sold himself to him to the Year of Jubilee. The price of his sale shall be according to the number of years; he shall be with him according to the time of a hired servant.

If there remain but a few years to the year of jubilee, then he shall reckon with him; according to his years of service he shall give back the price of his redemption.

As a servant hired year by year shall he be with him. He shall not rule with harshness over him in your sight.

If he isn’t redeemed by these means, then he shall be released in the Year of Jubilee: he and his children with him.