1 Chronicles 24:3, 6

With the help of Zadok a descendant of Eleazar and Ahimelek a descendant of Ithamar, David separated them into divisions for their appointed order of ministering.

The scribe Shemaiah son of Nethanel, a Levite, recorded their names in the presence of the king and of the officials: Zadok the priest, Ahimelek son of Abiathar and the heads of families of the priests and of the Levites—one family being taken from Eleazar and then one from Ithamar.