John Wesley on Numbers 21:1

King Arad - Or rather, the Canaanite King of Arad: for Arad is not the name of a man, but of a city or territory. And he seems to be called a Canaanite in a general sense, as the Amorites and others. The south - Of Canaan, towards the east, and near the dead sea. Of the spies - Not of those spies which Moses sent to spy the land, for that was done thirty eight years before this, and they went so privately, that the Canaanites took no notice of them, nor knew which way they came or went; but of the spies which he himself sent out to observe the marches and motions of the Israelites. Took some of them prisoners - Which God permitted for Israel's humiliation, and to teach them not to expect the conquest of that land from their own wisdom or valour.