Deuteronomy 31:23
And he gave Joshua the son of Nun a charge, and said, Be strong and of a good courage: for thou shalt bring the children of Israel into the land which I sware unto them: and I will be with thee. And he gave Joshua the son of Nun a charge, and said, Be strong and of a good courage: for thou shalt bring the children of Israel into the land which I sware unto them: and I will be with thee.
God chose Joshua to succeed Moses as leader and faithful shepherd of the Hebrew host, to bring the children of Israel into the promised land sworn to them, with solemn consecration to that important future work. The charge was given publicly before all the congregation, before the whole assembled congregation, solemnly committing the people to Joshua as Moses's leadership ended. Moses delivered that charge to Joshua in God's stead. Joshua was commanded to be strong and of good courage because he would bring Israel into that land, with the assurance that God would be with him.
The charge makes clear that Joshua, not Moses, would bring the people into the land. Its words were meant to strengthen and encourage Joshua for taking up the leadership Moses had long carried, consecrating him to the important future work of faithfully shepherding Israel. Through Moses laying his hands upon him, Joshua became full of the spirit of wisdom, so Israel listened to him and followed him as the Lord had commanded Moses.