Mishnayos Eruchin Perek 9 Mishnah 2

When the Jubilee Year is in effect, one may sell a field only until the Jubilee Year, at which point the field returns to its original owner. If the owner redeems the field before the Jubilee Year, the payment per annum is calculated by dividing the sale price by the number of years from the sale until the Jubilee Year. The owner returns the per annum payment multiplied by the number of years remaining until the Jubilee Year. If the owner of a field sold it to the first buyer for one hundred dinars and the first buyer then sold it to the second buyer for two hundred dinars, when the original owner redeems the field he calculates the payment only according to the price that he set with the first buyer, as it is stated: “And he calculates the years of its sale, and he returns the remainder to the man to whom he sold it” (Leviticus 25:27). If the owner of a field sold it to the first buyer for two hundred dinars and the first buyer then sold it to the second buyer for one hundred dinars, when the original owner redeems the field, he calculates the payment only according to the price that was paid by the last buyer, as it is stated: “And he calculates the years of its sale, and he returns the remainder to the man to whom he sold it.” The superfluous term “to the man” indicates that the verse is referring to the man who is currently in possession of the field. One may not sell his ancestral field that is located in a distant area and redeem with the proceeds a field that he sold in a nearby area. Likewise, he may not sell a low-quality field and redeem with the proceeds a high-quality field. And he may not borrow money and redeem the field, nor may he redeem the field incrementally, half now and half at a later date. But with regard to redeeming a field from the Temple treasury, it is permitted to redeem the field in any of these ways. This is a halakha where greater stringency applies with regard to redeeming a field from an ordinary individual than with regard to redeeming it from the Temple treasury.