Numbers 20:23-29

23When they were there, at the border of Edom's land, the Lord spoke to Moses and Aaron.

24He said, ‘Aaron will soon die. He will not go in to the land that I am giving to the Israelites. That is because you both refused to obey me at Meribah.

25Moses, you must take Aaron and his son Eleazar to climb up Hor mountain.

26Take the priest's clothes from Aaron and put them on Eleazar. Aaron will die there.’

27Moses did what the Lord told him to do. Moses, Aaron and Eleazar climbed up Hor mountain, while the Israelites watched.

28Moses took the priest's clothes from Aaron and he put them on Eleazar. Then Aaron died there, at the top of the mountain. Moses and Eleazar walked back down the mountain.

29The Israelites wept for 30 days because Aaron died.