Leviticus 25:9-10

25:9 You must sound loud horn blasts – in the seventh month, on the tenth day of the month, on the Day of Atonement – you must sound the horn in your entire land. 25:10 So you must consecrate the fiftieth year, and you must proclaim a release in the land for all its inhabitants. That year will be your jubilee; each one of you must return to his property and each one of you must return to his clan.