Gill, in his commentary, gives us a useful summary of this chapter.
‘In this chapter David makes Solomon king, 1 Chronicles 23:1, calls together the princes, priests, and Levites, numbers the latter, and assigns them their proper work, 1 Chronicles 23:2, divides them into three classes, 1 Chronicles 23:6, when the number of them was taken from twenty years of age, and upwards; the reasons of which are given, partly from the rest the land enjoyed, and partly from the several branches of their work and office in the temple, 1 Chronicles 23:24.’
When David was old, Solomon, his son became king over Israel. David then proceeds to organise Israel, first the leaders of Israel, 1 Chronicles 23:3-26 / 1 Chronicles 23:32. He then proceeds to organise the civil and military leaders, 1 Chronicles 27:1-34.
David organised the Levites who served from the age of 30 to 50, Numbers 4:3 / Numbers 4:23 / Numbers 4:47. Notice that David not only made preparations for the building of the temple before he died but also for the administration of temple affairs.
Coffman, in his commentary, says the following, concerning musical instruments.
‘David’s actions in this had no prior command of God to justify it. He violated the divine instructions that, Ye shall not add unto the word which I command you, neither shall ye diminish from it, Deuteronomy 4:2. David’s invention of instruments of music and his introduction of them into the worship of God was specifically condemned by the prophet Amos, Amos 5:23 Amos 6:5.’
David now separates the Levites into three classes, Gershon, Kohath, and Merari, Exodus 6:16. Ladan and Shimei were the immediate posterity of Gershon, the heads of families, Exodus 6:17. From the sons of Ladan, Jehiah was first, then Zetham, and Joel. They were not Ladan’s immediate sons, rather they descended from him.
Shelomith, Haziel, and Haran, were the first of the fathers of Ladan. Jahath, Zina, 1 Chronicles 23:10, Jeush, and Beriah were the sons of Shimei, descendants of his in the times of David.
Among the Levites, the descendants of Aaron were chosen for the priestly duties described in these verses. Being a member of the tribe of Levi wasn’t enough to be a priest, they had to be a descendant of this particular family of Aaron.
The priest’s duties were to sanctify the most holy things, burn incense before the Lord, minister to Him, Deuteronomy 10:8, and give the blessing in His name forever, Numbers 6:23.
The sons of Moses were Gershom and Eliezer, Exodus 18:3. Aaron’s sons were priests, but the sons of Moses, his brother, were reckoned as simple Levites, and therefore their houses are here enumerated.
The Pulpit Commentary, says the following, concerning Moses, the man of God.
‘This title is distinguished by the presence of the article. The Speaker’s Commentary mentions it as occurring only nine times, of which five instances belong to Moses, Deuteronomy 33:1 / Joshua 14:6 / 2 Chronicles 30:16 / Ezra 3:2, with the present place, three instances show the title applied to David, 2 Chronicles 8:14 / Nehemiah 12:24 / Nehemiah 12:36, and once it is applied to Shemaiah, 1 Kings 12:22. Although the sons of Moses belonged, as is here said, to the tribe of Levi, they did not belong to that portion which discharged priestly duties.’
Ellicott, in his commentary, says the following.
‘The sons of Uzziel constituted two houses and classes. The nine clans of Kohathite Levites are again rehearsed in 1 Chronicles 24:20-25. The sons of Merari, Mahli, and Mushi, are mentioned in Exodus 6:19 / Numbers 3:33 / 1 Chronicles 6:19.
Eleazar dies, and had no sons and so, his house merged with that of the sons of Kish, who married his daughters according to the Law, Numbers 36:6-9. The sons of Mahli, then, were represented in David’s day by the house of Kish, 1 Chronicles 24:29.
The Pulpit commentary, says the following.
‘Here we read about the houses of Merari, contributing four houses, and, with the nine Gershonite and eleven Kohathite, adding up to twenty-four. Merari is the third son of Levi, Genesis 46:11. The Mahli and Mushi of above verse were possibly grandson and son of Merari, if we follow the guidance of 1 Chronicles 6:47. Yet it would seem far more natural to explain this last-quoted passage by our 1 Chronicles 6:23, which would then parallel it. Otherwise, we must account for the name of Mahli habitually standing first, as here, as in 1 Chronicles 6:19, also, and 1 Chronicles 24:26, as also in Exodus 6:19 / Numbers 3:20 / Numbers 3:33, etc., in all of which places the statement is as distinct as in this verse, that Mahli and Mushi were sons. This and the following verse must be compared particularly with 1 Chronicles 24:26-29, the Jaaziah of which passage was evidently no son of Merari, on a par with Mahli and Mushi, but a later descendant. His descendants were three, Shoham, Zakkur, and Ibri, Beno being no proper name, but signifying ‘his son’.
Although it was stated that a Levite must be 30 years old to serve in the temple, 1 Chronicles 23:3, it appears that at the age of 20 years old, they could still qualify for certain work within the temple. It’s very possible this was some form of appreciation training until they got to 30 years of age, Numbers 8:24 / 2 Chronicles 31:17 / Ezra 3:8.
Notice that the duties for the sons of Aaron were very specific. They were to focus on everything that involved the sacrifices, from the gathering of the wood, preparing the animals to be sacrificed, and carrying out the actual sacrifices. All ceremonial washings and offerings were also in their care, Numbers 3:5-10 / Numbers 18:1-7.
Barnes, in his commentary, says the following.
‘Though the Levites were not allowed by themselves to offer sacrifice, yet there were many respects in which they assisted the priests when the sacrifice was offered, 2 Chronicles 29:34 / 2 Chronicles 35:11-12.’
2 Chronicles 29:25 tells us that David commanded this arrangements as he worked together with Gad, the king’s seer and Nathan the prophet. It also tells us that these arrangements were the commandment of the Lord by His prophets.
Coffman, in his commentary, says the following.
‘The Gargantuan significance of this chapter lies in the proof that during the life of David king of Israel, all of the extensive instructions and details written in the Book of Moses, The Pentateuch, were well known in Israel. As any good reference Bible will demonstrate, there is hardly a line in this chapter that does not tie in specifically with instructions in the Pentateuch. Furthermore, all of these instructions, except David’s use of instruments of music, were ancient, dating back to the times of Moses. They were not invented by David but honoured by him.’