Nehemiah 12:45
And the singers and the gatekeepers keep the charge of their God, even the charge of the cleansing -- according to the command of David and Solomon his son,
1 Chronicles 25:1-26
And David and the heads of the host separate for service, of the sons of Asaph, and Heman, and Jeduthun, who are prophesying with harps, with psalteries, and with cymbals, and the number of the workmen is according to their service.
1 Chronicles 23:28
for their station is at the side of the sons of Aaron, for the service of the house of Jehovah, over the courts, and over the chambers, and over the cleansing of every holy thing, and the work of the service of the house of God,
2 Chronicles 23:6
And none doth enter the house of Jehovah except the priests, and those ministering of the Levites (they go in for they are holy), and all the people keep the watch of Jehovah: