Numbers 16:39-40

39So Eleazar the priest took the bronze censers which the Levites who were burned had offered, and they were hammered out [into broad sheets] as a plating for the [bronze] altar [of burnt offering],

40as 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.