II Chronicles 8:14-15

And, according to the order of David his father, he appointed the divisions of the priests for their service, the Levites for their duties (to praise and serve before the priests) as the duty of each day required, and the gatekeepers by their divisions at each gate; for so David the man of God had commanded. They did not depart from the command of the king to the priests and Levites concerning any matter or concerning the treasuries.