What is the significance of the land being desolate?
Malbim: Now it begins to explain the Nimshal of "Kol Rosh la'Chali" (5). Just like the head is the Klal of the body, the land is the Klal of the nation. Every person in the nation will feel the desolation in the country and the capitol. Also refer to 1:7:2:2.
Will the cities truly be burned?
Radak: No. They will be so desolate that it is as if they were burned. This is like it says in the Tochachah "v'Haysah Artzechem Shemamah v'Areichem Yihyu Charbah" (Vayikra 26:33).
Malbim: Yes, partially. This corresponds to "v'Chol Levav Davai" (5). The heart is a lower level than the head. Even so, all the limbs feel its pain more than the head's pain, for when the heart is ill, all the limbs are faint and weak. The fire in the cities caused more desolation to people of the country.
It already said "Artzechem". What is "Admaschem"?
Radak: Seeded field and their trees.
Malbim: It is the land of every individual. Destruction and loss will strike every person; this is the Nimshal of "mi'Kaf Regel v'Ad Rosh Ein Bo Mesom" (6).
Who are "Zarim"?
Rashi: They are your enemies. They will consume it in front of your eyes. Radak - This is like it says in the Tochachah "Yisa Hashem Alecha Goy me'Rachok
Why does it say "Shemamah"?
Rashi, from Targum Yonasan: It is desolate from you, like an inheritance that switched to go to strangers. It is desolate of its owner.
What is "k'Mahpechas Zarim"?
Radak #1: The land is left desolate, for foreign Goyim come and consume what they find. You cannot work the land any more, for enemies come every day. It is like it says in the Tochachah "k'Mahpechas Sedom va'Amorah" (Devarim 29:22); they were Zarim (estranged) from fear of Elokim.
Radak citing Targum Yonasan: [In your liability, your land is desolate from you;] it is switched, and it is to foreigners.'
Radak #2: "Zarim" is like Zerem (a flow) of rain - the place that gushing rain flooded. Malbim - it destroys so much that no hope remains after it. There is no remnant and medicine for what it struck 1 .
Malbim: If a man's property was destroyed, and he and his enemies will get nothing, he is not so pained. Here, his enemies eat the land, but there is no hope for the owner in the future! This describes the Churban of Eretz Yehudah from when Melech Ashur came to conquer it. The first time, in the days of Achaz, he exiled the 10 tribes. The desolation was only to the Klal of the country - "Artzechem Shemamah." The cities [of Yehudah] were serene. The second time that he came, he seized the fortified cities of Yehudah - "Areichem Serufos Esh." Some individuals were still secure. The third time, he began to besiege Yerushalayim; the demise reached every person - "Admaschem l'Negdechem