Leviticus 25:15-17

according to the number of years after the jubile thou shalt buy of thy neighbour, and according unto the number of years of the fruits he shall sell unto thee: according to the multitude of years thou shalt increase the price thereof, and according to the fewness of years thou shalt diminish the price of it: for according to the number of the years of the fruits doth he sell unto thee. Ye shall not therefore oppress one another; but thou shalt fear thy God: for I am the LORD your God.