Numbers 20:28 - Ellicott's Commentary On The Whole Bible

And Aaron died there in the top of the mount. — The date of Aaron’s death, as we learn from Numbers 33:38, was the first day of the fifth month, in the fortieth year after the exodus, and his age a hundred and twenty-three years (Numbers 33:39), which accords with the statement contained in Exodus 7:7, that “Moses was fourscore years old, and Aaron fourscore and three years old, when they spake unto Pharaoh.” The difference in the circumstances of the death of the two brothers is remarkable. Both Moses and Aaron were excluded from the land of promise by reason of transgression. Both died upon the top of a mountain. But whilst Moses died in solitary grandeur, and the place of his burial was unknown, Aaron ascended the mount “in the sight of all the people,” and died in the presence of Moses and Eleazar. The death of Aaron was an indication of the imperfection of the Levitical priesthood. “They truly were many priests, because they were not suffered to continue by reason of death; but this man because he continueth ever, hath an unchangeable priesthood” (Hebrews 7:23-24).