Numbers 20:24-29

²⁴Aaron shall be gathered unto his people: for he shall not enter into the land which I have given unto the children of Israel, because ye rebelled against my word at the water of Meribah.

²⁵Take Aaron and Eleazar his son, and bring them up unto mount Hor:

²⁶and strip Aaron of his garments, and put them upon Eleazar his son: and Aaron shall be gathered unto his people, and shall die there.

²⁷And Moses did as the Lord commanded: and they went up into mount Hor in the sight of all the congregation.

²⁸And Moses stripped Aaron of his garments, and put them upon Eleazar his son; and Aaron died there in the top of the mount: and Moses and Eleazar came down from the mount.

²⁹And when all the congregation saw that Aaron was dead, they mourned for Aaron thirty days, even all the house of Israel.