29:30 King Hezekiah and the officials told the Levites to praise the Lord, using the psalms 1 of David and Asaph the prophet. 2 So they joyfully offered praise and bowed down and worshiped.
2 Chronicles 35:15
35:15 The musicians, the descendants of Asaph, manned their posts, as prescribed by David, Asaph, Heman, and Jeduthun the king’s prophet. 3 The guards at the various gates did not need to leave their posts, for their fellow Levites made preparations for them.