Where in Egypt will the sword be?
Malbim: It will spread in all of Egypt.
What is "Chalchalah"?
Rashi: It is trembling. When they hear the fall of Egypt, they will be afraid for themselves, lest Melech Bavel come against them.
Radak: When Kush will see people fall dead in Egypt, they will fear and be agitated lest the sword come against them, for they are neighbors and one nation - all of them 1 are sons of Cham.
Will only one Chalal fall dead in Egypt?
Radak: This is a Klal; there will be many Chalalim.
Whose Hamon will be taken?
Malbim: Egypt's.
What are its foundations?
Malbim: The nations that help it, listed in the coming verse. They are foundations of its kingship and Gevurah.