As a sign of especial favor God communicates to the pious the day of their death, that they may transmit their crowns to their sons. But God considered it particularly fitting to prepare Moses and Aaron for impending death, saying: "These two pious men throughout their lifetime did nothing without consulting Me, and I shall not therefore take them out of this world without previously informing them." 
When, therefore, Aaron's time approached, God said to Moses: "My servant Moses, who hast been 'faithful in all Mine house,' I have an important matter to communicate to thee, but it weighs heavily upon Me." Moses: "What is it?" God: "Aaron 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 waters of Meribah." Moses replied: "Lord of the world! It is manifest and known before the Throne of Thy glory, that Thou art Lord of all the world and of Thy creatures that in this world Thou hast created, so that we are in Thy hand, and in Thy hand it lies to do with us as Thou wilt. I am not, however, fit to go to my brother, and repeat to him Thy commission, for he is older than I, and how then shall I presume to go up to my older brother and say, 'Go up unto Mount Hor and die there!'" God answered Moses: "Not with the lip shalt thou touch this matter, but 'take Aaron and Eleazar his son, and bring them up unto Mount Hor.' Ascend thou also with them, and there speak with thy brother sweet and gentle words, the burden of which will, however, prepare him for what awaits him. Later when ye shall all three be upon the mountain, 'strip Aaron of his garments, and put them upon Eleazar his son, and Aaron shall be gathered unto his people, and shall die there.'  As a favor to Me prepare Aaron for his death, for I am ashamed to tell him of it Myself." 
When Moses heard this, there was a tumult in his heart, and he knew not what to do. He wept so passionately that his grief for the impending loss of his brother brought him to the brink of death himself. As a faithful servant of God, however, nothing remained for him to do, but to execute his Master's command, hence he betook himself to Aaron to the Tabernacle, to inform him of his death.
Now it had been customary during the forty years' march through the desert for the people daily to gather, first before the seventy elders, then under their guidance before the princes of the tribes, then for all of them to appear before Eleazar and Aaron, and with these to go to Moses to present to him their morning greeting. On this day, however, Moses made a change in this custom, and after having wept through the night, at the cock's crow summoned Eleazar before him and said to him: "Go and call to me the elders and the princes, for I have to convey to them a commission from the Lord." Accompanied by these men, Moses not betook himself to Aaron who, seeing Moses when he arose, asked: "Why hast thou made a change in the usual custom?" Moses: "God hath bidden me to make a communication to thee." Aaron: "Tell it to me." Moses: "Wait until we are out of doors." Aaron thereupon donned his eight priestly garments and both went out.
Now it had always been the custom for Moses whenever he went from his house to the Tabernacle to walk in the center, with Aaron at his right, Eleazar at his left, then the elders at both sides, and the people following in the rear. Upon arriving within the Tabernacle, Aaron would seat himself as the very nearest at Moses' right hand, Eleazar at his left, and the elders and princes in front. On this day, however, Moses changed this order; Aaron walked in the center, Moses at his right hand, Eleazar at his left, the elders and princes at both sides, and the rest of the people following.
When the Israelites saw this, they rejoiced greatly, saying: "Aaron now has a higher degree of the Holy Spirit than Moses, and therefore does Moses yield to him the place of honor in the center." The people loved Aaron better than Moses.  For ever since Aaron had become aware that through the construction of the Golden Calf he had brought about the transgression of Israel, it was his endeavor through the following course of life to atone for his sin. He would go from house to house, and whenever he found one who did not know how to recite his Shema', he taught him the Shema'; if one did not know how to pray he taught him how to pray; and if he found one who was not capable of penetrating into the study of the Torah, he initiated him into it.  He did not, however, consider his task restricted 'to establishing peace between God and man,' but strove to establish peace between the learned and the ignorant Israelites, among the scholars themselves, among the ignorant, and between man and wife.  Hence the people loved him very dearly, and rejoiced when they believed he had now attained a higher rank than Moses.
Having arrived at the Tabernacle, Aaron now wanted to enter, but Moses held him back, saying: "We shall now go beyond the camp." When they were outside the camp, Aaron said to Moses: "Tell me the commission God hath given thee." Moses answered: "Wait until we reach the mountain." At the foot of the mountain Moses said to the people: "Stay here until we return to you; I, Aaron, and Eleazar will go to the top of the mount, and shall return when we shall have heard the Divine revelation." All three now ascended.