Aaron's youngest son (Exodus 6:23). With Eleazar the elder he succeeded to the priestly offices vacated by the death of Nadab and Abihu, which he and Eleazar were forbidden to mourn (Exodus 28:1; Exodus 28:40; Exodus 28:48; Leviticus 10:1-2; Leviticus 10:6-7; Numbers 3:3-4; 1 Chronicles 24:2). Ithamar superintended the Gershonites who had charge of the curtains and hangings, and Merari who had charge of the pillars, Cords, and boards, on the march (Exodus 38:21; Numbers 4:21-33). Eleazar's family and chief men were more numerous than those of Ithamar. The high priesthood in Eli's person (probably on account of the high qualities for which he was made judge) passed to the line of Ithamar, but reverted to Eleazar's line in Zadok, because of Abiathar's share in Adonijah's rebellion; thus the prophecy against Eli was fulfilled (1 Samuel 2:31-35; 1 Samuel 3:12-14; 1 Kings 2:26-27; 1 Kings 2:35). (See ABIATHAR; ELI.)