Deuteronomy 31:1-3

Then Moses went and spoke these words to all Israel. And he said to them: “I am one hundred and twenty years old today. I can no longer go out and come in. Also the LORD has said to me, ‘You shall not cross over this Jordan.’ The LORD your God Himself crosses over before you; He will destroy these nations from before you, and you shall dispossess them. Joshua himself crosses over before you, just as the LORD has said.