According to David's appointment, 1Ch 24 1Ch 25, which was only for the ordinary service; but in extraordinary solemnities, such as this eminently was they all came together.
Related Commentaries of 2 Chronicles 5:11
2 Chronicles 5:11
11 And it came to pass, when the priests were come out of the holy place: (for all the priests that were present were sanctified, and did not then wait by course: