Numbers 27:18
And the LORD said unto Moses, Take thee Joshua the son of Nun, a man in whom is the spirit, and lay thine hand upon him; And the LORD said unto Moses, Take thee Joshua the son of Nun, a man in whom is the spirit, and lay thine hand upon him;
God chose Joshua the son of Nun to succeed Moses as Israel's leader and to lead Israel into the promised land. He was chosen because the Spirit was in him. Moses was to lay his hand upon Joshua and charge him publicly, thereby setting him apart for leadership, showing the people that he was divinely appointed, and sharing some of Moses's authority with him.
Joshua had been prepared by serving alongside Moses, gaining knowledge of the people, and proving faithful as one of the spies who urged Israel to trust God and enter the promised land. His wisdom, capability, faithfulness, devotion, courage, perseverance, integrity, and faith in God had already shown his fitness for leadership. He was to lead with the Lord as his counselor and support. The relationship between Moses and Joshua shows that experienced leaders are responsible to guide and support younger workers whom God raises up, and that refusing to do so can hinder the work and deprive them of blessings.