It was here on the top of this mountain that Aa'ron died, not by accident, but according to the Will of God. The LORD said, "Aa'ron shall be gathered unto his fathers: for he shall not enter into the land which I have given unto the children of Is'ra-el, because he rebelled against my word at the rock gushing water, of Mer'i-bah."
Just before Aa'ron died on the top of Mount Hor, Mo'ses removed the priestly garments which he wore, and placed them upon E-le-a'zar. Thus by Divine Appointment a son of Aa'ron took his place as High Priest of Is'ra-el. In his dying moments Aa'ron had the satisfaction of knowing that his office would not die with him, and that his work would be carried on by his own son. When the congregation of Is'ra-el learnt of the death of Aa'ron, a thirty day season of mourning was proclaimed. E-le-a'zar was named to take his place, and this appointment was confirmed by the people.
Taking advantage of this period of mourning, one of the kings of southern Ca'naan, whose name was A'rad, attacked the Is'ra-el-ites in the valley of A'ra-bah, and captured some of them. The Is'ra-el-ites then made a solemn vow unto the LORD that when they had taken possession of the Promised Land they would completely destroy A'rad's people. This vow was later accomplished, and the place was called Hor'mah, meaning "utter destruction."
While crossing this steep and barren land on their roundabout journey to a place where they might safely enter Ca'naan, the Is'ra-el-ites became very much discouraged, and began to make new complaints against Mo'ses. As a punishment for these murmurings, the LORD caused the poisonous snakes of that region to infest their camp in great numbers. They were called "fiery serpents" from the burning, deadly pain caused by their bites. Is'ra-el had complained for want of water, and the LORD sent a plague upon them which caused a thirst no water could quench; they had shown a preference for death in the wilderness, and the LORD sent death to many of them near the Promised Land.
Then the Is'ra-el-ites repented for their sins, pleaded with Mo'ses to speak to the LORD on their behalf, and asked that the poisonous snakes be driven away from the camp. The LORD not only drove the snakes away, but provided a cure for the people who had been bitten by them.
The LORD directed Mo'ses to make a serpent of brass, similar in every way to the poisonous serpents of the desert, and to place the brazen image on a high pole in the midst of the camps of Is'ra-el. Then those who had been bitten by the "fiery serpents" were told to look upon the "brazen serpent," and all who obeyed this command were healed at once. There was no way by which man could stop the deadly ravages of these serpents, nor was there any earthly remedy for their bites. But the means of cure provided by the LORD was free to all who obeyed His command to look upon the "brazen serpent."
