2 Chronicles 35:15-16

15The singers, the descendants of Asaph, were at their stations according to the command of David, Asaph, Heman, and Jeduthun the king’s seer. Also, the gatekeepers were at each temple gate. None of them left their tasks because their Levite brothers had made preparations for them.

16So all the service of the Lord was established that day for observing the Passover and for offering burnt offerings on the altar of the Lord, according to the command of King Josiah.