Albert Barnes Commentary Numbers 13:17

"And Moses sent them to spy out the land of Canaan, and said unto them, Get you up this way by the South, and go up into the hill-country:" — Numbers 13:17 (ASV)

Southward - Rather, “by the Negeb,” or south-country; a well-defined tract of territory forming the southernmost and least fertile portion of the land of Canaan and of the subsequent inheritance of Judah. It extended northward from Kadesh to within a few miles of Hebron, and from the Dead Sea westward to the Mediterranean .

Into the mountain - The hill-country of southern and central Canaan, mostly within the borders of Judah and Ephraim. It commences a few miles south of Hebron, and extending northward to the plain of Jezreel, runs out eventually northwestward into the sea in the headland of Carmel.