Numbers 20:27-29

²⁷So Moses did just as the Lord had commanded, and they went up to Mount Hor in the sight of all the congregation. ²⁸After Moses had stripped Aaron of his garments and put them on his son Eleazar, Aaron died there on the mountain top. Then Moses and Eleazar came down from the mountain. ²⁹When all the congregation saw that Aaron had died, all the house of Israel wept for Aaron thirty days.