And set him before Eleazar the priest, and before all the congregation; and give him a charge in their sight.

Wesley's Notes

27:19 Before all the congregation - That they may be witnesses of the whole action, and may acknowledge him for their supreme ruler. Give him charge - Thou shalt give him counsels and instructions for the right management of that great trust.

Matthew Henry's Concise Commentary

27:15-23 Envious spirits do not love their successors; but Moses was not one of these. We should concern ourselves, both in our prayers and in our endeavours, for the rising generation, that religion may be maintained and advanced, when we are in our graves. God appoints a successor, even Joshua; who had signalized himself by his courage in fighting Amalek, his humility in ministering to Moses, and his faith and sincerity in witnessing against the report of the evil spies. This man God appoints to succeed Moses; a man in whom is the Spirit, the Spirit of grace. He is a good man, fearing God and hating covetousness, and acting from principle. He has the spirit of government; he is fit to do the work and discharge the trusts of his place. He has a spirit of conduct and courage; he had also the Spirit of prophecy. That man is not fully qualified for any service in the church of Christ, who is destitute of the graces and gifts of the Holy Spirit, whatever human abilities he may possess. And in Joshua's succession we are reminded that the law was given by Moses, who by reason of our transgression could not bring us to heaven; but grace and truth came by Jesus Christ, for the salvation of every believer.