What is the question "Mi Shama"?
Malbim: The verse depicts that at the time of the Ge'ulah, the Yoledes sits on the birthing stool, and she has contractions (war of Gog). Then there is a wondrous birth, in two ways. Refer to 66:8:2:3.
What is the question "ha'Yuchal Eretz b'Yom Echad"?
Rashi: Will contractions come to a Yoledes to give birth to a land full of children in one day?
Radak: It uses the masculine for Eretz, like "v'Lo Nasa Osam ha'Aretz" (Bereishis 13:6). Ha'Yuchal is Pu'al conjugation of the Yotzei form of the verb (someone else terrified the land); the subject is not mentioned.
Malbim: (a) The Yoledes' contractions spread at once over the entire land, as if all women of the land had birth contractions in one day. (b) An entire nation is born at once. (The exiles gathered suddenly from the four corners of the world.)
Verse 8 said that she gave birth before contractions. Here it says that she had contractions!
Radak (7): The salvation will come suddenly, like giving birth to a female before contractions. Before the completion of the salvation, when all of Yisrael will gather in their land and their serenity will be complete, for a short time they will have like a Yoledes' contractions - "Chavi Chim'at Rega Ad Ya'avor Za'am" (26:20). It says "v'Nilkedah ha'Ir v'Nashasu ha'Batim" (Zecharyah 14:2). After these contractions "v'Yatza Hashem v'Nilcham ba'Goyim ha'Hem", "l"Es Erev Yihyeh Ohr" (Zecharyah 14:3, 7) - this is the birth after the contractions; "v'Yashvu Vah v'Cherem Lo Yihyeh Od" (ibid., 11).
