Deuteronomy 31:3-5

The LORD thy God, he will go over before thee, and he will destroy these nations from before thee, and thou shalt possess them: and Joshua, he shall go over before thee, as the LORD hath said. And the LORD shall do unto them as he did to Sihon and to Og, kings of the Amorites, and unto the land of them, whom he destroyed. And the LORD shall give them up before your face, that ye may do unto them according unto all the commandments which I have commanded you.