Arad was a Canaanite King, who attacked the children of Israel, when he heard that they were coming by the way of Atharim towards his land, when they journey from Egypt. He fought against Israel, and took some of them as prisoners, and after he had held some of them captive, that Israel vowed a vow to the Lord, and said, if thou wilt indeed deliver this people into my hand, then I will utterly destroy their cities. The Lord hearkened to the voice of Israel, and gave over King Arad and his Canaanite kingdom into the hand of Israel that they utterly destroyed them and their cities (Numbers 21:1-3).
When the children of Israel were invaded by king Arad, Israel was not ready, neither were they trained for war, which prompted them