The Hebrew Bible relates that, unlike Moses, who grew up in the Egyptian royal court, Aaron and his elder sister Miriam remained with their kinsmen in the northeastern region of the Nile Delta. When Moses first confronted the Egyptian king about the enslavement of the Israelites, Aaron served as his brother's spokesman to the Pharaoh (Exodus 7:1). Part of the Law given to Moses at Sinai granted Aaron the priesthood for himself and his male descendants, and he became the first High Priest of the Israelites.[12] Levitical priests or kohanim are traditionally believed and halakhically required to be of direct patrilineal descent from Aaron.[13]
According to the Book of Numbers, Aaron died at 123 years of age, on Mount Hor, in the fortieth year after the Israelites had come out of the land of Egypt.[14] Deuteronomy, however, places these events at Moseroth.[15][16]
–Wikipedia