(Numb. 20:22:) “Then setting out from Kadesh, the whole congregation [of the Children of Israel came to Mount Hor].” This text is related (to II Chron. 20:37), “Because you have joined with Ahaziah, the Lord will destroy your work.” [Similarly,] because they made an alliance with this wicked king to pass through his land, they lost this righteous man (i.e., Aaron). For that reason the death of Aaron is made [immediately] adjacent after the parashah about the king of Edom, [as stated] (Numb. 20:21-22), “so Israel turned away from them. Then setting out from Kadesh, the whole congregation [of the Children of Israel came to Mount Hor].” What is the meaning of “the whole congregation?”
A complete congregation, a congregation which would be entering the land, since those who had come out from Egypt had died. So these were the ones of whom it is written (in Deut. 4:4), “But you who clung to the Lord your God are all alive today.” (Numb. 20:22:) “Mount (hr) Hor (hr).” What is the meaning of “Mount Hor?” A mountain (hr) on top of a mountain (hr), like a small apple on a large apple.
Even though a cloud proceeded before them which lowered the high [places] and raised up the low, the Holy One, blessed be He, left [this] mountain as a sample, so that they would know what miracles the Holy One, blessed be He, had done for them; as He had not left a mountain in the desert, lest they become weary climbing and descending.
Moreover, although the cloud had made all the desert a plain, He left an elevated spot where the tabernacle would have its resting place. He also left three mountains: Mount Sinai for the Divine Presence, Mount Nebo for the burial of Moses, and Mount Hor for the burial of Aaron.