Why does it say "Nosenach" (masculine)?
Radak: Sometimes verses use the masculine for the nation, and sometimes the feminine for the Kenesiyah.
Who are "Bnei Kedem"?
Rashi: Kasdim and Aram - they are to the east.
Radak: They are Madai u'Faras. Even though Bnei Amon were spared from Nebuchadnetzar - his lottery fell on Yerushalayim [and not on Bnei Amon] - they should not rejoice over this. Madai u'Faras will inherit Amon's land!
What is the significance of giving birth to sons and daughters?
Radak: When they were one congregation, they succeeded, and served Me. Yonason translates like this.
Malbim: They multiplied in Eretz Yisrael, and were divided into two kingdoms. At first both of them served Me. They were divided in the days of Yaravam, and in the days of Achav [Shomron] began to serve Ba'al. They were divided in name, people [and whom they served].
To whose names does the second "u'Shmosan" refer?
Rashi: They are the initial names of the mothers.
Why is Shomron called Ahalah?
Rashi: It was from the beginning an Ohel (residence) for Yaravam's calves and Achav's Beis ha'Ba'al. Even though Shomron was not built until the days of Amri, Malchus Yisrael is called Shomron, for once it was built, it became the capitol. Radak ? it is her Ohel ? I have no portion in it.
Malbim: It was an Ohel by itself, separated from Hashem. It was "ha'Gedolah", i.e. the majority.
Why is Yerushalayim called Ahalivah?
Rashi: Ahali (My tent was) Vah (in it), and My Mikdash.
Radak: Ahali Vah; there I dwell. The Beis ha'Mikdash, the dwelling of My honor, is in it.
Malbim: My Ohel was in Yehudah; they were Tzadikim, for Hashem; Hashem dwelled among them.