Leviticus 25:48-52

48then after he is sold he may be redeemed. One of his brothers may redeem him,

49or his uncle or his cousin may redeem him, or a close relative from his clan may redeem him. Or if he grows rich he may redeem himself.

50He shall calculate with his buyer from the year when he sold himself to him until the year of jubilee, and the price of his sale shall vary with the number of years. The time he was with his owner shall be rated as the time of a hired worker.

51If there are still many years left, he shall pay proportionately for his redemption some of his sale price.

52If there remain but a few years until the year of jubilee, he shall calculate and pay for his redemption in proportion to his years of service.