'Duties' in the Bible

They shall carry out the duties for him and for the whole congregation before the Tent of Meeting, doing the service of the tabernacle.

So you shall appoint Aaron and his sons, and they shall observe and attend to their priesthood; but the layman (non-Levite) who approaches [the holy things] shall be put to death.”

The males who were numbered, every male from a month old and upward totaled 8,600, attending to the duties of the sanctuary.

They may assist their brothers in the Tent of Meeting to keep an obligation, but they shall do no [heavy or difficult] work. Thus you shall deal with the Levites concerning their obligations.”

And the Levites shall attend to your duty [as assistants] and to the duties of all the tent (tabernacle); only they shall not approach the articles of the sanctuary and the altar, or both they and you will die.

They shall join you and attend to the duties of the Tent of Meeting—all the service of the tent—and no stranger [no layman, anyone who is not a Levite] may approach you [and your sons].

So you shall attend to the duties of the sanctuary and the duties of the altar [of burnt offering and the altar of incense], so that there will no longer be wrath on the Israelites [as with Korah, Dathan, and Abiram].