Numbers 18:3

3 They are to fulfill their duties to you and their responsibilities for the Tent, but they must not have any contact with sacred objects in the Holy Place or with the altar. If they do, both they and you will be put to death.

Numbers 18:3 Meaning and Commentary

Numbers 18:3

And they shall keep thy charge, and the charge of all the
tabernacle
That is, the Levites, whatever Aaron and his sons, the priests, should charge them to do, or commit to their care and charge, that they should observe; as to watch and keep out all unfit persons, to take down and set up the tabernacle when needful only they shall not come nigh the vessels of the sanctuary;
as the ark and mercy seat in the holy of holies, the shewbread table, and candlestick in the holy place; wherefore when these were removed from place to place in journeying, they were covered, that they might not touch them as they carried them: and the altar;
both of incense and burnt offering, on neither of which might they offer: that neither they nor you also die:
the priests for suffering them to meddle with things that did not belong to them, and the Levites for intruding themselves.

Numbers 18:3 In-Context

1 The Lord said to Aaron, "You, your sons, and the Levites must suffer the consequences of any guilt connected with serving in the Tent of my presence; but only you and your sons will suffer the consequences of service in the priesthood.

2 Bring in your relatives, the tribe of Levi, to work with you and help you while you and your sons are serving at the Tent.

3 They are to fulfill their duties to you and their responsibilities for the Tent, but they must not have any contact with sacred objects in the Holy Place or with the altar. If they do, both they and you will be put to death.

4 They are to work with you and fulfill their responsibilities for all the service in the Tent, but no unqualified person may work with you.

5 You and your sons alone must fulfill the responsibilities for the Holy Place and the altar, so that my anger will not again break out against the people of Israel.