Deuteronomy 3:2-3

3:2 The Lord, however, said to me, “Don’t be afraid of him because I have already given him, his whole army, and his land to you. You will do to him exactly what you did to King Sihon of the Amorites who lived in Heshbon.” 3:3 So the Lord our God did indeed give over to us King Og of Bashan and his whole army and we struck them down until not a single survivor was left.