Why does it say "Amrech" (feminine) regarding Bnei Amon?
Radak: It refers to the Kenesiyah (assembly).
What is "He'ach"?
Rashi: It is an expression of Simchah. Radak - also Yonason translates so. The same applies to "He'ach He'ach Ra'asah Einenu" (Tehilim 35:21).
Over what did they rejoice?
Malbim: Over Churban ha'Mikdash, desolation of the land, and the Galus of Yisrael.
What is the meaning of "Ki Nichal"?
Rashi: Ninchal (we will inherit); it will be an inheritance to others.
Radak: The root is Nechalel (profaning). It has a Kamatz under the Ches, even though it is past tense, like the context and like "Nashamah". This is like "Hineni Mechalel Es Mikdashi" (24:21).
What is the meaning of "v'El Admas Yisrael Ki Nashamah"?
Radak: This is the land of the 10 tribes, which stood desolate from the sixth year of Chizkiyah, when they were exiled. Then [Amon] rejoiced, when Beis Yehudah, which remained, was exiled.
