Numbers 20:24-29
20:24 “Aaron will be gathered to his ancestors, for he will not enter into the land I have given to the Israelites because both of you rebelled against my word at the waters of Meribah.
20:25 Take Aaron and Eleazar his son, and bring them up on Mount Hor.
20:26 Remove Aaron’s priestly garments and put them on Eleazar his son, and Aaron will be gathered to his ancestors and will die there.”
20:27 So Moses did as the Lord commanded; and they went up Mount Hor in the sight of the whole community.
20:28 And Moses removed Aaron’s garments and put them on his son Eleazar. So Aaron died there on the top of the mountain. And Moses and Eleazar came down from the mountain.
20:29 When all the community saw that Aaron was dead, the whole house of Israel mourned for Aaron thirty days.