Numbers 20:27 And Moses did as the Lord commanded: and they went up into mount Hor in the sight of all the congregation. 28 And Moses stripped Aaron of his garments, and put them upon Eleazar his son; and Aaron died there in the top of the mount.
[Patriarchs & Prophets pp 426] Aaron committed a grievous sin when he yielded to the clamors of the people and made the golden calf at Sinai; and again, when he united with Miriam in envy and murmuring against Moses. And he, with Moses, offended the Lord at Kadesh by disobeying the command to speak to the rock that it might give forth its water. God intended that these great leaders of His people should be representatives of Christ. Aaron bore the names of Israel upon his breast.
He communicated to the people the will of God. He entered the most holy place on the Day of Atonement, “not without blood,” as a mediator for all Israel. He came forth from that work to bless the congregation, as Christ will come forth to bless His waiting people when His work of atonement in their behalf shall be ended. It was the exalted character of that sacred office as representative of our great High Priest that made Aaron's sin at Kadesh of so great magnitude.
With deep sorrow Moses removed from Aaron the holy vestments, and placed them upon Eleazar, who thus became his successor by divine appointment. For his sin at Kadesh, Aaron was denied the privilege of officiating as God's high priest in Canaan—of offering the first sacrifice in the goodly land, and thus consecrating the inheritance of Israel. Moses was to continue to bear his burden in leading the people to the very borders of Canaan.
Numbers 20:28 And Moses and Eleazar came down from the mount. 29 And when all the congregation saw that Aaron was dead, they mourned for Aaron thirty days, even all the house of Israel.
May The Lord add His blessing to the study of His word. God bless!