2 Chronicles 23:18-19

Moreover, Jehoiada placed the offices of the house of the LORD under the authority of the Levitical priests, whom David had assigned over the house of the LORD, to offer the burnt offerings of the LORD, as it is written in the law of Moses—with rejoicing and singing according to the order of David. He stationed the gatekeepers of the house of the LORD, so that no one would enter who was in any way unclean.