Matthew Poole and continuators on Numbers 16:38

38 The censers of these sinners against their own souls , let them make them broad plates for a covering of the altar : for they offered them before the LORD, therefore they are hallowed, and they shall be a sign unto the children of Israel.

(i. e.) Their own lives: who were the authors of their own death and destruction, Compare 1 King. 2. 23. Prov. 20. 2. This he saith for the vindication of Gods justice and his own ministry in this severe dispensation.

To wit, of burntofferings, which was made of wood, but covered with brass before this time, Exod. 27. 1, 2. to which this other covering was added for further ornament and security against the fire which was continually burning upon it.

A monument or warning to all strangers to take heed of invading the Priesthood, as it follows, ver. 40.