Why does it mention Kerovos and Rechokos?
Malbim: Both will deride you. The far one will mock you for Tum'ah ? Your name spread afar that you are Tamei. The close ones will mock you for your many troubles ? they will see the troubles amidst you.
What is "[Yiskalesu Vach] Temeis ha'Shem"?
Rashi: They say about you that you are [the nation] that was Metamei its name. They were called Am Kadosh ? children of their Maker, and they caused themselves to be called "Am Temei Sefasayim" (Yeshayah 6:5).
Radak: You have Shem Tum'ah among the Goyim. Aside from Tum'ah of your body, your name is Tamei.
What is "Rabas ha'Mehumah"?
Radak: Your troubles are many ? hunger, sword and plague.
