Leviticus 25:51-53

New International Version - UK

⁵¹ If many years remain, they must pay for their redemption a larger share of the price paid for them. ⁵² If only a few years remain until the Year of Jubilee, they are to compute that and pay for their redemption accordingly. ⁵³ They are to be treated as workers hired from year to year; you must see to it that those to whom they owe service do not rule over them ruthlessly.