Midrasch zu Schemot 28:40

34) (Vayikra 10:2): "And a fire came out from before the L–rd": We are hereby taught that a fire came forth from the holy of holies and burned their souls. Abba Yossi b. Dostai says: Two strands of fire came forth from the holy of holies and parted into four, and entered, two into the nostrils of one, and two, into the nostrils of the other, and burned them, but not their garments, it being written (Vayikra 10:2) "and it consumed them," but not their garments. And it is written (Vayikra 10:5) "And they carried them in their tunics": In the tunics of the carried (their garments not having been burned) or the tunics of the carriers? It is, therefore, written (Shemoth 28:40): "And for the sons of Aaron (here, the carried,) shall you make tunics," (and not for the sons of the Levites; here, the carriers).