Leviticus 25:20-24

And if ye shall say, What shall we eat the seventh year? behold, we shall not sow, nor gather in our increase:

Then I will command my blessing upon you in the sixth year, and it shall bring forth fruit for three years.

And ye shall sow the eighth year, and eat yet of old fruit until the ninth year; until her fruits come in ye shall eat of the old store.

The land shall not be sold for ever: for the land is mine; for ye are strangers and sojourners with me.

And in all the land of your possession ye shall grant a redemption for the land.