For the children of Ammon and Moab stood up against the inhabitants of mount Seir, utterly to slay and destroy them: and when they had made an end of the inhabitants of Seir, every one helped to destroy another.
The kids from Ammon and Moab fought the people on Mount Seir, trying to kill and destroy them completely. After they finished with the people of Seir, everyone turned on each other and destroyed each other.