1 Chronicles 24:4, 31

A larger number of leaders were found among Eleazar’s descendants than among Ithamar’s, and they were divided accordingly: sixteen heads of families from Eleazar’s descendants and eight heads of families from Ithamar’s descendants.

They also cast lots, just as their relatives the descendants of Aaron did, in the presence of King David and of Zadok, Ahimelek, and the heads of families of the priests and of the Levites. The families of the oldest brother were treated the same as those of the youngest.