Is it permissible to dispose of the three additional hectares of land that the father purchased, and which were later found by measurement to exceed the area stated in the contract?

If you bought a plot of land and its area turned out to be larger than what was agreed upon, the sale is valid according to the majority of scholars. However, there is a difference of opinion regarding entitlement to the excess area. The fatwa adopted by us is that the excess area belongs to the seller. If he is alive, it is his right; otherwise, it belongs to his heirs.