Joshua 12:7,8

Ver. 7, 8. And these are the kings of the country which Joshua and the children of Israel smote, on this side Jordan— The author wrote in the country of Canaan, properly so called; and this region was, with respect to him, on this side Jordan, to the west of that river. With respect to the limits which he describes of this conquered land, he specifies them as in ver. 17 of the foregoing chapter. Here Calmet is of opinion, that instead of translating even unto the mount Halak, &c. we should render it, even to the mountains of separation, which serve as limits betwixt the land of Canaan and that of Seir, and rise towards Idumea. Nothing can better suit with those mountains which lay to the south of Judaea, than this name mountains of separation; to be convinced, we need only cast our eyes over any accurate map of the country.