1 Chronicles 24:3-4

Together with Zadok  from the descendants of Eleazar and Ahimelech from the descendants of Ithamar, David divided them according to the assigned duties of their service. Since more leaders were found among Eleazar’s descendants than Ithamar’s, they were divided accordingly: sixteen heads of ancestral families  were from Eleazar’s descendants, and eight heads of ancestral families were from Ithamar’s.