King James Version
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.English Standard Version
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.New International Version
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.