See Joshua 9:1. “The south” was the Negeb Numbers 13:17. Render “the springs” “slopes.” The word here means the district of undulating ground between “the vale” (or שׁפלה shephêlâh) last named and “the hills.”
Related Commentaries of Joshua 10:40
Joshua 10:40
40 So Joshua smote all the country of the hills, and of the south, and of the vale, and of the springs, and all their kings: he left none remaining, but utterly destroyed all that breathed, as the LORD God of Israel commanded.