When the Canaanite king of Arad, who ruled in the arid southern plain, heard that the Israelites were coming on the Atharim road, he fought against Israel and took some of them captive.
References for Numbers 21:1
Then Israel made a solemn promise to the LORD and said, "If you give this people into our hands, we will completely destroy their city."
The LORD heard the voice of Israel and handed the Canaanites over. They completely destroyed them and their cities, so the name of the place is called Hormah.
References for Numbers 21:3