To whom should he say this?
Radak: To Yerushalayim, like it says above (19) "El Toch Yerushalayim."
What do we learn from "Eretz Lo Metoharah Hi Lo Gushmah b'Yom Za'am"?
Zevachim 113a #1: We read the beginning of the verse incredulously. Is not Eretz Yisrael Tahor, like we find that it was spared from the flood?!
Zevachim 113a #2: We read the end of the verse incredulously. Eretz Yisrael is not Tahor! Was it not flooded?! (Surely it was!)
Rashi: It did not receive the proper rain to be Metaher it on a day of anger. Targum Yonasan says, it did not do good deeds to shield it on a cursed day.
Radak #1: This is like it is called above "Temeis ha'Shem" (5). "Lo Metoharah" is Tamei, like "Asher Lo Yihyeh Tahor" (Devarim 23:11).
Radak #2: It did not purify itself from its Tum'ah, i.e. it did not repent.
Malbim: The destruction in Eretz Yisrael is compared to the flood's destruction of the land. They perverted their ways like Dor ha'Mabul. However, the flood rain purified the land; all Tum'ah was erased, like one who washes filth with water; the land was Metoharah. This did not happen after the Churban. When Hashem was angry, rain did not descend to purify the land. The Churban was via fire, and not via water.
What is the grammatical form of "Gushmah"?
Radak #1: The Hei is Mapik Hei. It is a noun with the same grammatical form as Godel. With the pronoun (the suffix Hei), the first letter of the root receives a Shuruk, like "Haleluhu k'Rov Gudelo" (Tehilim 150:2). Rain did not fall on a day of anger. Hashem was angry, and withheld Shamayim and there was no rain, like it says "Pen Yifteh Levavchem v'Sartem va'Avadtem Elohim Acherim?; v'Atzar Es ha'Shamayim? v'Lo Yihyeh Matar" (Devarim 11:16-17).
Radak #2: It is a Dagush verb, just the Dagesh is omitted, like happens often. The Mapik Hei is to beautify the pronunciation, like "v'Sa'alumah Yotzei Ohr" (Iyov 28:11), "v'Gulah Al Roshah" (Zecharyah 4:2).
