Leviticus 25:27

‘In proportion to the extent of the years you shall increase its price, and in proportion to the fewness of the years you shall diminish its price, for it is the number of crops it produces that he is selling to you.

or his uncle or his uncle’s son may redeem him, or one of his blood relatives from his family may redeem him; or if he prospers, he may redeem himself.

‘Indeed, the seller will not return to himself what he sold as long as they both live; for the vision regarding all their multitude will not return empty, nor will any of them strengthen his life by his iniquity.