1)
Why does it say "Gam Atem Kushim"?
1.
Rashi: This refers to when Yisrael were exiled there, on the other side of the rivers of Kush.
2.
Malbim: Also you reviled Yisrael, therefore you will be victims of My sword.
2)
How do we explain "Chalelei Charbi Hemah"?
1.
Radak #1: It says "Atem" (second person) and Hemah (third person); verses often switch between these, e.g. "Kulam Tashuvu" (Iyov 17:10).
2.
Radak #2: It means ka'Hemah; the prefix Kaf is omitted. You will be victims of My sword, like them (Amon and Mo'av, which were mentioned above (9)). Even though you are far from Eretz Yisrael, you did evil to Yisrael; also you will be killed via the sword.
