were over the laborers and supervised all who did the work, task by task. Some of the Levites were secretaries, officers, and gatekeepers.
KJV
Also [they were] over the bearers of burdens, and [were] overseers of all that wrought the work in any manner of service: and of the Levites [there were] scribes, and officers, and porters.
ASV
Also they were over the bearers of burdens, and set forward all that did the work in every manner of service: and of the Levites there were scribes, and officers, and porters.