“Aaron will be gathered to his people; he will not enter the land that I have given the Israelites, because both of you rebelled against My command at the waters of Meribah.
The chapter began with the funeral of Miriam, and it ends with the funeral of her brother Aaron. When death comes into a family, it often strikes double. Israel had not improved the former affliction they were under, by the death of the prophetess, and therefore, soon after, God took away their priest, to try if they would lay that to heart.
Commenting on Numbers 20:22-29
Take Aaron and Eleazar his son,.... His eldest son, who was to succeed him in the priesthood, and did: and bring them up unto Mount Hor; to the top of it, they being now at the foot of it, where the people of Israel lay encamped.
Aaron shall be gathered unto his people--In accordance with his recent doom, he, attired in the high priest's costume, was commanded to ascend that mountain and die. But although the time of his death was hastened by the divine displeasure as a punishment for his sins, the manner of his death was arranged in tenderness of love, and to do him honor at the close of his earthly service.