1)
Do we find that they were chased?
1.
Radak: Yes - "Nasan Hashem Me'arvim Al Bnei Amon Mo'av v'Har Se'ir" (Divrei ha'Yamim II, 20:22).
2)
What is the comparison to a storm?
1.
Malbim: A storm blows in one direction. So He will chase them to flee.
3)
What is "Sufah"?
1.
Malbim: It is a hurricane; it blows in a circle. He will make them go back opposite their faces; via this, he will confound them.
