1)
What is "va'Asher Diber Pi Hashem Alav"?
1.
Rashi: Who is the Navi to whom Hashem speaks, who can tell why all this punishment came. Radak, Malbim - regarding a Chacham, the verse asks who understands it by himself.
2)
What is the meaning of "Avdah ha'Aretz Nitzesah ka'Midbar"?
1.
Malbim: Even though Hashem punished Yisrael [other times], the land was never so desolate that it is not proper to be settled. This shows that there was great anger, and there is no hope to return to their land when they will fix their deeds - "v'Ra'u Es Makos ha'Aretz...; Gafris va'Melach Sereifah Chol Artzah...; v'Amru... Al Mah Asah Hashem Kachah la'Aretz ha'Zos" (Devarim 29:21-23).
