Leviticus 25:9-10

You shall then sound a ram’s horn abroad on the tenth day of the seventh month; on the day of atonement you shall sound a horn all through your land. You shall thus consecrate the fiftieth year and proclaim a release through the land to all its inhabitants. It shall be a jubilee for you, and each of you shall return to his own property, and each of you shall return to his family.