Albert Barnes Commentary 2 Chronicles 23:7

"And the Levites shall compass the king round about, every man with his weapons in his hand; and whosoever cometh into the house, let him be slain: and be ye with the king when he cometh in, and when he goeth out." — 2 Chronicles 23:7 (ASV)

Compare 2 Kings 11:8 and 2 Kings 11:11. The soldiers and the Levites in the temple were probably intermixed in about equal proportions.