Albert Barnes Commentary Joshua 10:40

"So Joshua smote all the land, the hill-country, and the South, and the lowland, and the slopes, and all their kings: he left none remaining, but he utterly destroyed all that breathed, as Jehovah, the God of Israel, commanded." — Joshua 10:40 (ASV)

See (Joshua 9:1). “The south” was the Negeb (Numbers 13:17). Interpret “the springs” as “slopes.” The word here means the district of undulating ground between “the vale” (or שׁפלה, shephelah) last named and “the hills.”