The Bible – Old Testament
The descendants of Aaron also were divided into classes. The sons of Aaron were Nadab, Abihu, Eleazar, and Ithamar.
Nadab and Abihu died before their father, leaving no sons; therefore only Eleazar and Ithamar served as priests.
David, with Zadok, a descendant of Eleazar, and Ahimelech, a descendant of Ithamar, assigned the functions for the priestly service.
But since the descendants of Eleazar were found to be more numerous than those of Ithamar, the former were divided into sixteen groups, and the latter into eight groups, each under its family head.
Their functions were assigned impartially by lot, for there were officers of the holy place, and officers of the divine presence, descended both from Eleazar and from Ithamar.
1 The scribe Shemaiah, son of Nethanel, a Levite, made a record of it in the presence of the king, and of the leaders, of Zadok the priest, and of Ahimelech, son of Abiathar, and of the heads of the ancestral houses of the priests and of the Levites, listing two successive family groups from Eleazar before each one from Ithamar.
The first lot fell to Jehoiarib, the second to Jedaiah,
the third to Harim, the fourth to Seorim,
the fifth to Malchijah, the sixth to Mijamin,
the seventh to Hakkoz, the eighth to Abijah,
the ninth to Jeshua, the tenth to Shecaniah,
the eleventh to Eliashib, the twelfth to Jakim,
the thirteenth to Huppah, the fourteenth to Ishbaal,
the fifteenth to Bilgah, the sixteenth to Immer,
the seventeenth to Hezir, the eighteenth to Happizzez,
the nineteenth to Pethahiah, the twentieth to Jehezkel,
the twenty-first to Jachin, the twenty-second to Gamul,
the twenty-third to Delaiah, the twenty-fourth to Maaziah.
This was the appointed order of their service when they functioned in the house of the LORD in keeping with the precepts given them by Aaron, their father, as the LORD, the God of Israel, had commanded him.
Of the remaining Levites, there were Shubael, of the descendants of Amram, and Jehdeiah, of the descendants of Shubael;
Isshiah, the chief, of the descendants of Rehabiah;
Shelomith of the Izharites, and Jahath of the descendants of Shelomith.
The descendants of Hebron were Jeriah, the chief, Amariah, the second, Jahaziel, the third, Jekameam, the fourth.
The descendants of Uzziel were Micah; Shamir, of the descendants of Micah;
Isshiah, the brother of Micah; and Zechariah, a descendant of Isshiah.
The descendants of Merari were Mahli, Mushi, and the descendants of his son Uzziah.
The descendants of Merari through his son Uzziah: Shoham, Zaccur, and Ibri.
Descendants of Mahli were Eleazar, who had no sons,
and Jerahmeel, of the descendants of Kish.
The descendants of Mushi were Mahli, Eder, and Jerimoth. These were the descendants of the Levites according to their ancestral houses.
They too, in the same manner as their relatives, the descendants of Aaron, cast lots in the presence of King David, Zadok, Ahimelech, and the heads of the priestly and levitical families; the more important family did so in the same way as the less important one.
1  Ahimelech, son of Abiathar: see note on ⇒ 1 Chron 18:16.