When will this occur?
Radak: At the time of the gathering of exiles in the days of Mashi'ach. Now you are guaranteed this consolation.
Malbim: It will be after they are redeemed in the days of Koresh.
Who are "Goyim Rabim"?
Radak: Gog and Magog, and many nations with him.
Malbim: After they returned in Bayis Sheni, many nations gathered against them in different generations, e.g. Yevanim and afterwards Romiyim, and afterwards during the entire Galus. This will be until the final gathering in the days of Gog and Magog.
What is the significance of saying "Techenaf"?
Rashi: Now Tziyon will be liable for its sins, and punished for them.
Radak: They think in their hearts, now she will be liable for her sins. She will be destroyed now, like she was destroyed before.
Malbim: Sometimes they want that Tziyon will flatter them ? it will be submissive to them and subjugated to them, like a slave flatters his master. Yavan and Romi wanted Yisrael to be indebted to pay taxes to them. Also refer to 4:11:4:2.
What is the meaning of "v'Sachaz b'Tziyon Eineinu"?
Rashi: Our eyes will see in it what we longed to see. Radak ? this is like "uv'Oyvai Ra'asah Eini" (Tehilim 54:9). "V'Sachaz" is like v'Sechezah.
Malbim: Sometimes the nations think that the visions that the Nevi'im saw about Tziyon were for them, for they entered in place of Yisrael, and Hashem will dwell on them. So the Yishmaelim think; this is why they will gather an army against Yerushalayim to conquer it. And this is why Gog and Magog will gather to conquer Yerushalayim!
