I Chronicles 23:1-32 NKJV
So when David was old and full of days, he made his son Solomon king over Israel.
And he gathered together all the leaders of Israel, with the priests and the Levites. Now the Levites were numbered from the age of thirty years and above; and the number of individual males was thirty-eight thousand. Of these, twenty-four thousand were to look after the work of the house of the LORD, six thousand were officers and judges, four thousand were gatekeepers, and four thousand praised the LORD with musical instruments, “which I made,” said David, “for giving praise.”
Also David separated them into divisions among the sons of Levi: Gershon, Kohath, and Merari.
Of the Gershonites: Laadan and Shimei. The sons of Laadan: the first Jehiel, then Zetham and Joel—three in all. The sons of Shimei: Shelomith, Haziel, and Haran—three in all. These were the heads of the fathers’ houses of Laadan. And the sons of Shimei: Jahath, Zina, Jeush, and Beriah. These were the four sons of Shimei. Jahath was the first and Zizah the second. But Jeush and Beriah did not have many sons; therefore they were assigned as one father’s house.
The sons of Kohath: Amram, Izhar, Hebron, and Uzziel—four in all. The sons of Amram: Aaron and Moses; and Aaron was set apart, he and his sons forever, that he should sanctify the most holy things, to burn incense before the LORD, to minister to Him, and to give the blessing in His name forever. Now the sons of Moses the man of God were reckoned to the tribe of Levi. The sons of Moses were Gershon and Eliezer. Of the sons of Gershon, Shebuel was the first. Of the descendants of Eliezer, Rehabiah was the first. And Eliezer had no other sons, but the sons of Rehabiah were very many. Of the sons of Izhar, Shelomith was the first. Of the sons of Hebron, Jeriah was the first, Amariah the second, Jahaziel the third, and Jekameam the fourth. Of the sons of Uzziel, Michah was the first and Jesshiah the second.
The sons of Merari were Mahli and Mushi. The sons of Mahli were Eleazar and Kish. And Eleazar died, and had no sons, but only daughters; and their brethren, the sons of Kish, took them as wives. The sons of Mushi were Mahli, Eder, and Jeremoth—three in all.
These were the sons of Levi by their fathers’ houses—the heads of the fathers’ houses as they were counted individually by the number of their names, who did the work for the service of the house of the LORD, from the age of twenty years and above.
For David said, “The LORD God of Israel has given rest to His people, that they may dwell in Jerusalem forever”; and also to the Levites, “They shall no longer carry the tabernacle, or any of the articles for its service.” For by the last words of David the Levites were numbered from twenty years old and above; because their duty was to help the sons of Aaron in the service of the house of the LORD, in the courts and in the chambers, in the purifying of all holy things and the work of the service of the house of God, both with the showbread and the fine flour for the grain offering, with the unleavened cakes and what is baked in the pan, with what is mixed and with all kinds of measures and sizes; to stand every morning to thank and praise the LORD, and likewise at evening; and at every presentation of a burnt offering to the LORD on the Sabbaths and on the New Moons and on the set feasts, by number according to the ordinance governing them, regularly before the LORD; and that they should attend to the needs of the tabernacle of meeting, the needs of the holy place, and the needs of the sons of Aaron their brethren in the work of the house of the LORD.
NKJV: New King James Version