Albert Barnes Commentary 2 Chronicles 23:18

"And Jehoiada appointed the officers of the house of Jehovah under the hand of the priests the Levites, whom David had distributed in the house of Jehovah, to offer the burnt-offerings of Jehovah, as it is written in the law of Moses, with rejoicing and with singing, according to the order of David." — 2 Chronicles 23:18 (ASV)

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 (Numbers 18:1–7), and of the Levites alone to praise God with singing and music (1 Chronicles 23:5; 1 Chronicles 25:1–7).