Notes on the Bible, by Albert Barnes, , at sacred-texts.com
Compare the history in Kings (the marginal reference). Both accounts were probably drawn from a common source. The writer of Kings treated the points of civil and historic importance, the later author of Chronicles collected the notices of the part taken in the transactions by the sacred order to which he probably belonged.
2 Chronicles 23:1
The five names do not occur in Kings; only, and incidentally, the five divisions of the royal guard (Kg2 11:5 note).
2 Chronicles 23:2
Jehoiada was unwilling to trust the success of the revolution wholly and entirely to the royal body-guard. Accordingly, the captains collected from the cities of Judah a strong body of Levites and the chief of the fathers of Israel (i. e. "Judah," see Ch2 20:34 note) who were brought up to Jerusalem.
2 Chronicles 23:3
By "all the congregation" here is meant the persons referred to in Ch2 23:2.
2 Chronicles 23:4
The writer of Chronicles relates the orders that were given to the Levites, the author of Kings those received by the royal body-guard (Kg2 11:5 note).
2 Chronicles 23:6
Keep the watch of the Lord - i. e. guard against any attempt that might be made by the Baal-worshippers to force their way through the courts into the temple.
2 Chronicles 23:7
Compare Kg2 11:8, Kg2 11:11. The soldiers and the Levites in the temple were probably intermixed in about equal proportions.
2 Chronicles 23:8
And took every man his men ... - i. e. the relief, already organized by Jehoiada into three bodies Ch2 23:4-5, was further strengthened by the members of the outgoing "course," who were associated in the work to be done.
2 Chronicles 23:13
At the entering in - i. e. at, or near, the opening from the main chamber of the temple into the holy of holies.
2 Chronicles 23:16
Between him ... - In Kg2 11:17 the covenant is said to have been made "between the Lord," etc. To the writer of Chronicles Jehoiada was God's representative, and received the pledges of king and people.
2 Chronicles 23:18
The priests the Levites - Rather, with the versions, "the priests and the Levites." It was the duty of the priests alone to offer the burnt offerings Num 18:1-7, and of the Levites alone to praise God with singing and music Ch1 23:5; Ch1 25:1-7.
2 Chronicles 23:20
The high gate - See Kg2 11:19 note.