1 Chronicles 24:3-31

With the help of Zadok of the sons of Eleazar, and Ahimelech of the sons of Ithamar, David organized them according to the appointed duties in their service. Since more chief men were found among the sons of Eleazar than among the sons of Ithamar, they organized them under sixteen heads of fathers’ houses of the sons of Eleazar, and eight of the sons of Ithamar. They divided them by lot, all alike, for there were sacred officers and officers of God among both the sons of Eleazar and the sons of Ithamar. These also, the head of each father’s house and his younger brother alike, cast lots, just as their brothers the sons of Aaron, in the presence of King David, Zadok, Ahimelech, and the heads of fathers’ houses of the priests and of the Levites.