Aaron
Archimandrite Nikifor’s Biblical Encyclopedia
(lofty, mountain, mountain of light, teacher, enlightened one; a name shared with that of Harun, so common in the East) was the first high priest of the Hebrew people and the elder brother of the prophet and lawgiver Moses (Exod. 28:1). Son of Amram and Jochebed, he was of the tribe of Levi and was three years older than his brother Moses. Because of Moses’ slowness of speech, Aaron had to speak for him before the people and before Pharaoh, king of Egypt, for which reason he is called by God “the mouth of Moses” and “his prophet” (Exod. 4:16; 7:1); at the same time he was to help his brother during the journey of the Hebrews from Egypt to the land of Canaan.
Aaron took to wife Elisheba, daughter of Amminadab, and had by her four sons: Nadab, Abihu, Eleazar, and Ithamar. The first two were put to death by God for offering to the Lord strange fire, and in this way the priesthood was confirmed upon the remaining brothers left alive (Exod. 6:23).