These were the divisions of the descendants of Aaron: The sons of Aaron were Nadab, Abihu, Eleazar and Ithamar.
References for 1 Chronicles 24:1
But Nadab and Abihu died before their father did, and they had no sons; so Eleazar and Ithamar served as the priests.
References for 1 Chronicles 24:2
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.
References for 1 Chronicles 24:3
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 divided them impartially by casting lots, for there were officials of the sanctuary and officials of God among the descendants of both Eleazar and Ithamar.
References for 1 Chronicles 24:5
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.
References for 1 Chronicles 24:6