1)
What is "mi'Kol Naflam Ra'ashah ha'Aretz"?
1.
Radak: This is like one who falls from a high place to a low place. The sound of his fall is heard. So Edom, according to their great height and haughtiness, when their fall comes, it will be heard from afar like an earthquake.
2)
Why does it say "Tze'akah b'Yam Suf Nishma Kolah"?
1.
Radak: [The sound of their fall] will be heard until Yam Suf. This is an exaggeration. It mentions Yam Suf, for it is opposite Eretz Edom. Even though a great Midbar is in between, the sound of Edom will be heard there on the day it falls.
2.
Malbim: This sound was heard when Yisrael passed through the Yam Suf. The Egyptians drowned and screamed a great, bitter cry.
