Bible Verses About The Levites: Divided them into four classed

Of which, twenty and four thousand were to set forward the work of the house of the LORD; and six thousand were officers and judges:

Moreover four thousand were porters; and four thousand praised the LORD with the instruments which I made, said David, to praise therewith.

And David divided them into courses among the sons of Levi, namely, Gershon, Kohath, and Merari.