Why does it say "Alah Achlah Eretz"?
Rashi: It was due to the sin of vain Shevu'os.
Radak: Even though Yisrael and other nations were punished for other sins, the greatest is swearing falsely in Hashem's name. Churban of the land is usually for this. 'For all Aveiros, the sinner is punished; here, he and the entire world are punished - 'Alo v'Chachesh; ... Te'eval ha'Aretz" (Hoshe'a 4:2-3).
Malbim: Since they transgressed the Torah, the Alah (curse) written in Netzavim consumed and burned the land - "Gafris va'Melach Serefah Chol Artzah" (Devarim 29:22).
What is "va'Yeshmu"?
Radak: It is an expression of Shemamah (desolation).
Malbim: [The residents] were guilty. They caused the desolation and burning of the land.
What is the meaning of "Charu"?
Rashi: It is an expression of dry and thirsty in a heat wave. It is like "Nachar Mapu'ach" (Yirmeyah 6:29).
Radak: It is dryness and burning, i.e. eradication.
Malbim: They were singed [from the fire that burned the land].
Why does it say "v'Nish'ar Enosh Miz'ar"?
Malbim: Enosh are small people, the poor; few will remain.
