Why does Hashem speak "b'Esh Kin'asi"?
Malbim: Edom and Pelishtim take vengeance via hatred. They wanted Eretz Yisrael to remain desolate, not to take it, just so it would be desolate. Hashem will take vengeance against them with Kin'ah.
What is "She'eris Goyim"?
Malbim: It is Pelishtim. Egypt already struck them; only a remnant remained. Edom was "Kula" (intact).
Why is there an Aleph at the end of "Kula"?
Radak: We find like this ? "v'Hayah Lachem l'Zara" (Bamidbar 11:20), "Ken Yiten li'Ydido Shena" (Tehilim 127:2).
What is the significance of "Artzi"?
Radak citing Targum Yonasan: The land that houses My Shechinah.
What is "Migrashah la'Vaz"?
Rashi: They saw [Yisrael] expelled [from their land]; it was given to be plundered.
Radak: Migrashah is a noun in place of Makor (infinitive), like "u'Lemasa Es ha'Machanos" (Bamos 10:2). It is as if it says "to expel her to be despoiled." Also Yonason translates so.
Malbim: They did not want to 'inherit' Eretz Yisrael to build it, rather, so it will remain Migrash, i.e. an empty area in front of the city without houses, fields or vineyards. They wanted this for disgrace; therefore, punishments were prophesized for them.