Why does it mention idols?
Rashi: Refer to 10:10:2:1.
Radak: Even though these kingdoms have idols, the idols did not have power to save their land from my hand.
Why does it say "u'Fsileihem mi'Yrushalayim umi'Shomron"?
Rashi (from Sifri Ha'azinu 318): This teaches that Resha'im of Yisrael (in Yerushalayim and Shomron) used to supply their images of idolatry to all the surrounding nations. Since those who served the idols fell to my hand, and their idols did not save them, so Shomron and Yerushalayim will not be saved.
Radak: They were stronger than Yerushalayim and Shomron. Since I overpowered them, all the more so (I will overpower Shomron and Yerushalayim).
Malbim: This is a Kal v'Chomer that he can conquer Yerushalayim. I conquered nations that constantly served idolatry, and dedicated their kingdoms to idolatry and called them on their names - the kingdom of idol Ploni. It was proper that the idol wage their battle and help them. All the more so I will conquer Yerushalayim, which has less idols!
