1 Chronicles 24:2-4

New International Version

² But Nadab and Abihu died before their father did,^(A) and they had no sons; so Eleazar and Ithamar served as the priests. ³ With the help of Zadok^(B) a descendant of Eleazar and Ahimelek a descendant of Ithamar, David separated them into divisions for their appointed order of ministering. ⁴ 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.