תַּהֲר֥וּ חֲשַׁ֖שׁ תֵּ֣לְדוּ קַ֑שׁ רוּחֲכֶ֕ם אֵ֖שׁ תֹּאכַלְכֶֽם׃
Ye conceive chaff, ye shall bring forth stubble; Your breath is a fire that shall devour you.
Rashi on Isaiah
chaff (חֲשַׁשׁ) a kind of chaff, something that is easily ignited.
Rashi on Isaiah
your breath is fire From your body shall emanate breath of fire and will consume the chaff and the stubble.