Numbers 16:40

40 as the LORD directed him through Moses. This was to remind the Israelites that no one except a descendant of Aaron should come to burn incense before the LORD, or he would become like Korah and his followers.

Read Numbers 16:40 Using Other Translations

To be a memorial unto the children of Israel, that no stranger, which is not of the seed of Aaron, come near to offer incense before the LORD; that he be not as Korah, and as his company: as the LORD said to him by the hand of Moses.
to be a reminder to the people of Israel, so that no outsider, who is not of the descendants of Aaron, should draw near to burn incense before the LORD, lest he become like Korah and his company--as the LORD said to him through Moses.
This would warn the Israelites that no unauthorized person—no one who was not a descendant of Aaron—should ever enter the LORD ’s presence to burn incense. If anyone did, the same thing would happen to him as happened to Korah and his followers. So the LORD ’s instructions to Moses were carried out.

What does Numbers 16:40 mean?

John Gill's Exposition of the Bible
Numbers 16:40

[To be] a memorial unto the children of Israel
The whole body of them; this explains what is meant by sign, ( Numbers 16:38 ) ; that it was to put or keep in mind what follows:

that no stranger which [is] not of the seed of Aaron come near to offer
incense before the Lord;
not only any Gentile but any Israelite, and not any Israelite only, but any Levite; none but those of the family of Aaron might offer incense before the Lord;

that he be not as Korah and as his company;
this makes it clear that Korah perished at this time, though it is nowhere expressed; and it seems pretty plain from hence that he perished by fire, as his company, the two hundred fifty men with censers, did:

as the Lord said unto him by the hand of Moses;
either to Korah, who is the immediate antecedent, and who perished as the Lord had told him by Moses he should; so some understand it, mentioned by Aben Ezra and Jarchi; or else to Aaron, as they interpret it; and then the sense is, that none but those of Aaron's seed should offer incense, as the Lord had declared to him by Moses; see ( Numbers 3:10 ) ; or it may be rather to Eleazar, as Abendana, who did as the Lord spake to him by Moses, took up the censers of the men that were burnt, and got them beaten into broad plates, and covered the altar of burnt offering with them.

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