Numbers 16:5, 40

and he spoke to Korah and all his company, saying, “In the morning the LORD will show who belongs to Him, and who is holy, and will bring him near to Himself; the one whom He will choose He will bring near to Himself. [2 Tim 2:19]

as a reminder to the sons of Israel so that no layman—that is, one who is not of the descendants of Aaron should approach to offer incense before the LORD; so that he will not become like Korah and as his company—just as the LORD had said to him through Moses.