Numbers 33:37-39

American Standard Version

³⁷ And they journeyed from Kadesh, and encamped in mount Hor, in the edge of the land of Edom.

³⁸ And Aaron the priest went up into mount Hor at the commandment of Jehovah, and died there, in the fortieth year after the children of Israel were come out of the land of Egypt, in the fifth month, on the first day of the month. ³⁹ And Aaron was a hundred and twenty and three years old when he died in mount Hor.