2 Chronicles 35:15-16

15The singers, the descendants of Asaph, were at their stations according to the commandment of David, Asaph, Heman and Jeduthun, the king’s seer. The gatekeepers were at every gate. They did not need to depart from their posts for their fellow Levites provided for them.

16So on that day the entire service of Adonai was prepared to keep the Passover and to offer burnt offerings upon the altar of Adonai according to the command of King Josiah.