John Calvin Commentary Deuteronomy 31:14

"And Jehovah said unto Moses, Behold, thy days approach that thou must die: call Joshua, and present yourselves in the tent of meeting, that I may give him a charge. And Moses and Joshua went, and presented themselves in the tent of meeting." — Deuteronomy 31:14 (ASV)

And the Lord said to Moses. Joshua is now appointed to take the place of Moses through a solemn ceremony. This was not only so that he might be held in greater reverence by the people, but also so that he might be presented before God and thus acknowledge his dedication to His service. Indeed, his being brought before the door of the tabernacle was a form of consecration. God also declares that He will give him a charge, which means He will instruct him in the performance of his duties.

Furthermore, the appearance of God's glory in the cloud was no less effective in encouraging Joshua personally than in giving public distinction to his high office. For he would never have been recognized as Moses' successor unless this visible approval from God had secured the people's submission to him.