Deuteronomy - Chapter 31

In this chapter Moses tells the people that God has told him that God, himself, will cross over the Jordan ahead of the people, and he will destroy the nations before them.

This promise is fulfilled in the book of Joshua.  In Joshua chapter 5, just before the fall of Jericho, Joshua sees a man standing in front of him with a sword drawn.  That man tells Joshua that he has come as the commander of the army of the Lord.  The man then allows Joshua to fall down before him and tells Joshua to take off his sandals for the ground is holy.  This shows that the man is an appearance of Jesus, who will lead his people into victory in the promised land.