To be cut off from the nation is a common punishment in the book of Leviticus. It consistently means the disinheritance and excommunication of an individual from the community. This presumptuous act would result in the expulsion of an individual from the covenant community.
20 Tout homme pur peut manger de la chair; mais celui qui, se trouvant en état d'impureté, mangera de la chair du sacrifice d'actions de grâces qui appartient à l'Eternel, celui-là sera retranché de son peuple.