Numbers 21:1
When the Canaanite king of Arad, who lived in the Negev, heard that Israel was coming by the way of the Atharim, he fought against Israel and took some of them captive — the Canaanite king of Arad initiates hostilities; he hears of Israel's approach and attacks. The text provides no reason for the attack beyond territorial defense. Arad, a southern Canaanite kingdom, represents the first direct military confrontation in Transjordan (distinct from the miraculous deliverances of the wilderness period).