What do we do with the excess? We distribute it as broadly as possible and as equably as possible, and we endow the legatees of that distribution with as much claim to the entitlement as is possible.
Rights are the allottments of excess under the rules of equality. We learn this from the laws of Yom haKippurim.
Land is a surrogate for the graceful distribution of all allottments. They are distributed equably, and they are subject to sabbatical laws. The sabbatical laws are a form of copyleft: you can use it but not as private property. These entitlements can only be used as script for civic empowerment.
The sabbatical and the jubilee are both institutions of civic participation and civic empowerment.