"And you shall sanctify the fiftieth year"Leviticus 25:10.

We are commanded to sanctify the fiftieth year, the Jubilee Year, by abstaining from agricultural work and rendering all the land's produce ownerless and free for all to take—just as we are commanded to do during the Shemitah (Sabbatical) Year.

This mitzvah is only practiced in the Land of Israel, and only when all of the tribes are settled therein, each in their ancestral portion of the Land.