Numbers 33:37-39

Revised Standard Version

³⁷ And they set out from Kadesh, and encamped at Mount Hor, on the edge of the land of Edom.

³⁸ And Aaron the priest went up Mount Hor at the command of the Lord, and died there, in the fortieth year after the people of Israel had come out of the land of Egypt, on the first day of the fifth month. ³⁹ And Aaron was a hundred and twenty-three years old when he died on Mount Hor.