Southward, i.e. into the southern part of Canaan, which was the nearest part, and the worst too, being dry and desert, Joshua 15:1,3 Jud 1:15 Psalms 126:4, and therefore fittest for them to enter and pass through with less observation. Into the mountain, i.e. into the mountainous country, and thence into the valleys, and so take an exact survey of the whole land.
Related Commentaries of Numbers 13:17
Numbers 13:17
17 And Moses sent them to spy out the land of Canaan, and said unto them, Get you up this way southward, and go up into the mountain: