Deuteronomy 31:3-5

31:3 As for the Lord your God, he is about to cross over before you; he will destroy these nations before you and dispossess them. As for Joshua, he is about to cross before you just as the Lord has said. 31:4 The Lord will do to them just what he did to Sihon and Og, the Amorite kings, and to their land, which he destroyed. 31:5 The Lord will deliver them over to you and you will do to them according to the whole commandment I have given you.