The writer of Chronicles relates the orders that were given to the Levites, the author of Kings those received by the royal body-guard (2 Kings 11:5 note).
Related Commentaries of 2 Chronicles 23:4
2 Chronicles 23:4
4 This is the thing that ye shall do; A third part of you entering on the sabbath, of the priests and of the Levites, shall be porters of the doors;a