23 God said to Moses and Aaron at Mount Hor at the border of Edom, 24 "It's time for Aaron to be gathered into the company of his ancestors. He will not enter the land I am giving to the People of Israel because you both rebelled against my orders at the Waters of Meribah. 25 So take Aaron and his son Eleazar and lead them up Mount Hor. 26 Remove Aaron's clothes from him and put them on his son Eleazar. Aaron will be gathered there; Aaron will die." 27 Moses obeyed God's command. They climbed Mount Hor as the whole congregation watched. 28 Moses took off Aaron's clothes and put them on his son Eleazar. Aaron died on top of the mountain. Then Moses and Eleazar came down from the mountain. 29 The whole congregation, getting the news that Aaron had died, went into thirty days of mourning for him.
Matthew Henry's Commentary on Numbers 20:23-29
Commentary on Numbers 20:22-29
(Read Numbers 20:22-29)
God bids Aaron prepare to die. There is something of displeasure in these orders. Aaron must not enter Canaan, because he had failed in his duty at the waters of strife. There is much of mercy in them. Aaron, though he dies for his transgression, dies with ease, and in honour. He is gathered to his people, as one who dies in the arms of Divine grace. There is much significancy in these orders. Aaron must not enter Canaan, to show that the Levitical priesthood could make nothing perfect; that must be done by bringing in a better hope. Aaron submits, and dies in the method and manner appointed; and, for aught that appears, with as much cheerfulness as if he had been going to bed. It was a great satisfaction to Aaron to see his son, who was dear to him, preferred; and his office preserved and secured: especially, to see in this a figure of Christ's everlasting priesthood. A good man would desire, if it were the will of God, not to outlive his usefulness. Why should we covet to continue any longer in this world, than while we may do some service in it for God and our generation?