Moses wanted to inform his brother of his impending death, but knew not how to go about it. At length he said to him: "Aaron, my brother, hath God given anything into thy keeping?" "Yes," replied Aaron. "What, pray?" asked Moses. Aaron: "The altar and the table upon which is the shewbread hath He given into my charge." Moses: "It may be that He will now demand back from thee all that He hath given into thy keeping." Aaron: "What, pray?" Moses: "Hath He not entrusted a light to thee?" Aaron: "Not one light only but all seven of the candlestick that now burn in the sanctuary." Moses had, of course, intended to call Aaron's attention to the soul, "the light of the Lord," which God had given into his keeping and which He now demanded back. As Aaron, in his simplicity, did not notice the allusion, Moses did not go into further particulars, but remarked to Aaron: "God hath with justice called thee an innocent, simple-hearted man."
While they were thus conversing, a cave opened up before them, whereupon Moses requested his brother to enter it, and Aaron instantly acquiesced. Moses was now in a sad predicament, for, to follow God's command, he had to strip Aaron of his garments and to put them upon Eleazar, but he knew not how to broach the subject to his brother. He finally said to Aaron: "My brother Aaron, it is not proper to enter the cave into which we now want to descend, invested in the priestly garments, for they might there become unclean; the cave is very beautiful, and it is therefore possible that there are old graves in it." Aaron replied, "Thou art right." Moses then stripped his brother of his priestly garments, and put them upon Aaron's son, Eleazar. 
As it would have been improper if Aaron had been buried quite naked, God brought about the miracle that, as soon as Moses took off one of Aaron's garments, a corresponding celestial garment was spread over Aaron, and when Moses had stripped him of all his priestly garments, he found himself arrayed in eight celestial garments. A second miracle came to pass in the stripping of Aaron's garments, for Moses was enabled to take off the undermost garments before the upper. This was done in order to satisfy the law that priests may never use their upper garments as undergarments, a thing Eleazar would have had to do, had Moses stripped off Aaron's outer garments first and with these invested his son. 
After Eleazar had put on the high priest's garments, Moses and Aaron said to him: "Wait for us here until we return out of the cave," and both entered it. At their entrance they beheld a couch spread, a table prepared, and a candle lighted, while ministering angels surrounded the couch. Aaron then said to Moses: "How long, O my brother, wilt thou still conceal the commission God hath entrusted to thee? Thou knowest that He Himself, when for the first time He addressed thee, with His own lips declared of me, 'When he seeth thee, he will be glad in his heart.' Why, then, dost thou conceal the commission God hath entrusted to thee? Even if it were to refer to my death, I should take it upon myself with a cheerful countenance." Moses replied: "As thou thyself dost speak of death, I will acknowledge that God's words to me do concern thy death, but I was afraid to make it known to thee. But look now, thy death is not as that of the other creatures of flesh and blood; and not only is thy death a remarkable one, but see! The ministering angels have come to stand by thee in thy parting hour." 
When he spoke of the remarkable death that awaited Aaron, Moses meant to allude to the fact that Aaron, like his sister Miriam and later Moses, was to die not through the Angel of Death, but by a kiss from God.  Aaron, however, said: "O my brother Moses, why didst not thou make this communication to me in the presence of my mother, my wife, and my children?" Moses did not instantly reply to this question, but tried to speak words of comfort and encouragement to Aaron, saying: "Dost thou not know, my brother, that thou didst forty years ago deserve to meet thy death when thou didst fashion the Golden Calf, but then I stood before the Lord in prayer and exhortation, and saved thee from death. And now I pray that my death were as thine! For when thou diest, I bury thee, but when I shall die, I shall have no brother to bury me. When thou diest, thy sons will inherit thy position, but when I die, strangers will inherit my place." With these and similar words Moses encouraged his brother, until he finally looked forward to his end with equanimity.
Aaron lay down upon the adorned couch, and God received his soul. Moses then left the cave, which immediately vanished, so that none might know or understand how it had happened. When Eleazar saw Moses return alone, he said to him: "O my teacher, where is my father?" Moses replied: "He has entered Paradise." Then both descended from the mountain into the camp.  When the people saw Moses and Eleazar return without Aaron, they were not at all in the mood to lend faith to the communication of Aaron's death. They could not at all credit that a man who had overcome the Angel of Death was now overcome by him. Three opinions were then formed among the people concerning Aaron's absence. Some declared that Moses had killed Aaron because he was jealous of his popularity; some thought Eleazar had killed his father to become his successor as high priest; and there was also some who declared that he had been removed from earth to be translated to heaven. Satan had so incited the people against Moses and Eleazar that they wanted to stone them. Moses hereupon prayed to God, saying: "Deliver me and Eleazar from this unmerited suspicion, and also show to the people Aaron's bier, that they may not believe him to be still alive, for in their boundless admiration for Aaron they may even make a God of him." God then said to the angels: "Lift up on high the bier upon which lies My friend Aaron, so that Israel may know he is dead and my not lay hand upon Moses and Eleazar." The angels did as they were bidden,  and Israel then saw Aaron's bier floating in the air, while God before it and the angels behind intoned a funeral song for Aaron. God lamented in the words, "He entereth into peace; they rest in their beds, each one that walketh in his uprightness," whereas the angels said: "The law of truth was in his mouth, and unrighteousness was not found in his lips: he walked with Me in peace and uprightness, and did turn many away from iniquity."