Números 33:38

38 At the Lord's command Aaron the priest went up Mount Hor, where he died on the first day of the fifth month of the fortieth year after the Israelites came out of Egypt.

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.