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 remember the children of Israel, no non-Aaron descendant should approach to offer incense to God. This way, it won't be like Korah and his group, as God spoke through Moses.