Why will Yisrael not have any thorns around them to pain them?
Rashi: He prophesized about Amon, Mo'av, Pelishtim, Edom Tzor and Tzidon ? the neighbors of Eretz Yisrael will all be destroyed. Malbim ? this is the purpose of their fall! Also Tzidon used to pain Yisrael.
What is "Silon Mam'ir [v'Kotz Mach'iv]"?
Rashi: Silon is a kind of thorn. Mam'ir is paining, like "Tzara'as Mem'eres" (Vayikra 13:52). Radak ? "Kotz Mach'iv" is a repetition of the matter in different words. It is a Mashal.
Radak citing Targum Yonasan: A king who arouses hatred and rulers who pain.
What is the meaning of "ha'Shatim"?
Rashi: They plunder.
Why does it repeat "v'Yad'u Ki Ani Hashem"? The previous two verses said so!
Malbim: They will know that I, Hashem, wage the battle of Yisrael.