What is "Saf Ra'al"?
Rashi: It is a Kli that envelops. Saf is "ba'Dam Asher ba'Saf" (Shemos 12:22). Ra'al is an expression of desolation ? closure of the heart and limbs, that they have no strength, like a person wrapped in a cloak [and cannot move his limbs]. This is like "veha'Beroshim Har'alu" (Nachum 2:4), "veha'Sheros veha'Re'alos" (Yeshayah 3:19). A Mishnah says, women of Madai go out Re'ulos [on Shabbos ? Shabbos 65a].
Radak: This is like "Kos ha'Tar'elah" (a cup of poison); one who drinks it, he dies. So all those who camp around (besiege) Yerushalayim will perish.
Malbim: It is explained in Yechezkel (Perakim 32, 37-38) that in the end of days, Gog and Magog (from Edom) will gather to seize Yerushalayim from the Yishmaelim. They will fight and kill each other, and Hashem will fight against both of them to judge them for the evils that they did to Yisrael in Churban ha'Bayis and during the Galus. Yerushalayim will be a cup of poison for all nations ? they will drink, get drunk, and be bewildered.
Why does it say "v'Gam Al Yehudah"?
Rashi: The Goyim that will besiege Yerushalayim, they will force Bnei Yehudah to besiege it. So Yonason translates. Radak ? the poison will be also on Yehudah initially. It will be a great affliction for them [to besiege Yerushalayim]. After the Ge'ulah, Gog and Magog will come against Yerushalayim. They will not be concerned to conquer the rest of Eretz Yisrael first. They will say, after we conquer Yerushalayim, [automatically] the rest of Eretz Yisrael will be under us.
Malbim: Before they besiege Yerushalayim, they will besiege Yehudah, and do many evils to Yisrael.
