Deuteronomy 31:2-6

And he said to them, “I am a hundred and twenty years old today; I am no longer able to come and go, and the LORD has said to me, ‘You shall not cross this Jordan.’ It is the LORD your God who will cross ahead of you; He will destroy these nations before you, and you shall dispossess them. Joshua is the one who will cross ahead of you, just as the LORD has spoken. The LORD will do to them just as He did to Sihon and Og, the kings of the Amorites, and to their land, when He destroyed them. The LORD will deliver them up before you, and you shall do to them according to all the commandments which I have commanded you. Be strong and courageous, do not be afraid or tremble at them, for the LORD your God is the one who goes with you. He will not fail you or forsake you.”