Why will Hashem make the chiefs of Yehudah like fire?
Rashi: They will fight against those who brought them to besiege Yerushalayim].
Radak: When I will send lunacy among the Goyim, Alfei Yehudah will realize that it is from Hashem. They and [commoners of] Yehudah with them will strike Goyim on the right and left.
Malbim: They will confront or make war with both sides (Edom and Yishmael).
What is "k'Kiyor Esh"?
Rashi: Like a great bonfire. Kiyor is like Kirah (an oven). Also Menachem explains so.
Radak: It is a coal. Kiyor is like "Tanu v'Kirayim" (Vayikra 11:35).
Why does it mention wood and Amir (straw)?
Radak: They are ready to burn with fire. So the Nochrim are prepared for eradication via confusion and lunacy that Hashem will send in them.
Malbim: They bring wood to a Kirh, and burn them there. So they will bring Goyim (Gog's army) to be burned there. A flame burns straw where the straw is. So they will burn the Yishmaelim in their place and land.
What is the significance of "v'Yashvah Yerushalayim Od Tachteha bi'Yrushalayim"?
Rashi: The Nochrim thought to destroy Yerushalayim from being a city. It will dwell in its place ? what is called Yerushalayim nowadays.
Malbim: This time, they will not reach Yerushalayim to besiege it until the third time; Perek 13 says that the city will be conquered. Our verse teaches that [this time] they will not be able to harm it. It says bi'Yrushalayim, for in Yechezkel (Perek 48) it is explained that in the future, Yerushalayim will be 45 Mil south of where it is today; the current Yerushalayim will be for the Kohanim and the Beis ha'Mikdash. During war of Gog and Magog, Yerushalayim will be in its initial place. It will be moved only after all the wars.
