The Jubilee year was the year of release, when every man's inheritance of land was to be restored to its original owner. See Leviticus 25:10.
Related Commentaries of Numbers 36:4
Numbers 36:4
4 And when the jubile of the children of Israel shall be, then shall their inheritance be put unto the inheritance of the tribe whereunto they are received: so shall their inheritance be taken away from the inheritance of the tribe of our fathers.