1 Chronicles 24:3-5

David, with Zadok of the sons of Eleazar and Ahimelech of the sons of Ithamar, divided them according to their offices for their ministry. Since more chief men were found from the descendants of Eleazar than the descendants of Ithamar, they divided them thus: there were sixteen heads of fathers’ households of the descendants of Eleazar and eight of the descendants of Ithamar, according to their fathers’ households. Thus they were divided by lot, the one as the other; for they were officers of the sanctuary and officers of God, both from the descendants of Eleazar and the descendants of Ithamar.