1 Chronicles 24:2-4

Darby Translation

² And Nadab and Abihu died before their father, and had no children; and Eleazar and Ithamar exercised the priesthood.

³ And David distributed them, both Zadok of the sons of Eleazar, and Ahimelech of the sons of Ithamar, according to their office in their service.

⁴ And there were more head-men found of the sons of Eleazar than of the sons of Ithamar, and [thus] were they divided: of the sons of Eleazar there were sixteen heads of fathers' houses, and eight of the sons of Ithamar according to their fathers' houses.