וַֽיִּקְרְב֗וּ וַיִּשָּׂאֻם֙ בְּכֻתֳּנֹתָ֔ם אֶל־מִח֖וּץ לַֽמַּחֲנֶ֑ה כַּאֲשֶׁ֖ר דִּבֶּ֥ר מֹשֶֽׁה׃
他們就上前來，把死者連同身上穿著的內袍抬到營外，照摩西所說的。
Rashi
בכתנתם IN THEIR GARMENTS — in those of the dead (not in their own garments). This tells us that their garments had not been destroyed by fire, but their souls alone (neither their clothing nor bodies showed signs of burning; they had been struck by fire inwardly): there entered into their nostrils something like two threads of fire which burnt them to death (Sifra, Shemini, Mechilta d'Miluim 2 34; Sanhedrin 52a).
Sforno
בכתנותם אל מחוץ למחנה, they did not bother to remove their holy vestments from them seeing that these had already become ritually impure.
Chizkuni
בכתנותם, “in their tunics;” not the tunics of the pallbearers since only priests, not Levites, wore those tunics.