Deuteronomy 31:2-8

2And he said to them, “I am a hundred and twenty years old today; I am no longer able to come in and go out [as your spiritual and military leader], and the Lord has said to me, ‘You shall not cross this Jordan.’

3It 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 go across before you [to lead you], just as the Lord has said.

4The 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.

5The Lord will hand them over to you, and you shall do to them in accordance with all the commandments which I have commanded you.

6Be strong and courageous, do not be afraid or tremble in dread before them, for it is the Lord your God who goes with you. He will not fail you or abandon you.”

7Then Moses called to Joshua and said to him in the sight of all [the people of] Israel, “Be strong and courageous, for you will go with this people into the land which the Lord has sworn to their fathers to give them, and you will give it to them as an inheritance.

8It is the Lord who goes before you; He will be with you. He will not fail you or abandon you. Do not fear or be dismayed.”