Deuteronomy 30:15-31:6

See, I set before you this day life and prosperity, death and adversity. For I command you this day, to love the Lord your God, to walk in His ways, and to keep His commandments, His laws, and His rules, that you may thrive and increase, and that the Lord your God may bless you in the land that you are about to enter and possess. But if your heart turns away and you give no heed, and are lured into the worship and service of other gods, I declare to you this day that you shall certainly perish; you shall not long endure on the soil that you are crossing the Jordan to enter and possess. I call heaven and earth to witness against you this day: I have put before you life and death, blessing and curse. Choose life--if you and your offspring would live--by loving the Lord your God, heeding His commands, and holding fast to Him. For thereby you shall have life and shall long endure upon the soil that the Lord swore to your ancestors, Abraham, Isaac, and Jacob, to give to them. Moses went and spoke these things to all Israel. He said to them: I am now one hundred and twenty years old, I can no longer be active. Moreover, the Lord has said to me, "You shall not go across yonder Jordan." The Lord your God Himself will cross over before you; and He Himself will wipe out those nations from your path and you shall dispossess them.--Joshua is the one who shall cross before you, as the Lord has spoken. The Lord will do to them as He did to Sihon and Og, kings of the Amorites, and to their countries, when He wiped them out. The Lord will deliver them up to you, and you shall deal with them in full accordance with the Instruction that I have enjoined upon you. Be strong and resolute, be not in fear or in dread of them; for the Lord your God Himself marches with you: He will not fail you or forsake you.