And the LORD said to me, "Do not fear him, for I have delivered him and all his people and his land into your hand; you shall do to him as you did to Sihon king of the Amorites, who dwelt at Heshbon.'
Deuteronomy 3:2
Surrounding context
3:1 "Then we turned and went up the road to Bashan; and Og king of Bashan came out against us, he and all his people, to battle at Edrei.
3:2 And the LORD said to me, "Do not fear him, for I have delivered him and all his people and his land into your hand; you shall do to him as you did to Sihon king of the Amorites, who dwelt at Heshbon.'
3:3 "So the LORD our God also delivered into our hands Og king of Bashan, with all his people, and we attacked him until he had no survivors remaining.