1 Chronicles 6:50

Eleazar . The third son of Aaron (by Elisheba, daughter of Amminadab, and descended from Judah through Pharez) is the sea whose descendants are given here, inasmuch as he was appointed chief of the Levites ( Numbers 3:32 ); ministered as a priest with his brother Ithamar, even before the death of Aaron; and succeeded him as high priest ( Numbers 20:28 ). It was in Eleazar's family that the high priesthood remained (as above) till the time of Eli, who was descended from Ithamar, and it returned again to the line of Eleazar in Zadok, fulfilling the intimation of 1 Samuel 2:30 .