1 Chronicles 23:3-6

DouayRheims(i) 3 And the Levites were numbered from the age of thirty years, and upwards: and there were found of them thirty-eight thousand men. 4 Of these twenty-four thousand were chosen, and distributed unto the ministry of the house of the Lord: and six thousand were the overseers and judges. 5 Moreover four thousand were porters: and as many singers singing to the Lord with the instruments, which he had made to sing with. 6 And David distributed them into courses by the families of the sons of Levi, to wit, of Gerson, and of Caath, and of Merari.