Why does it specify "Erech Apayim u'Gdal Ko'ach"?
Rashi: He has the ability to take vengeance. He does not rush his vengeance, for He is Erech Apayim. In any case, "v'Nake Lo Yenake."
Radak, Malbim: His Midah is to delay His anger at Resha'im [from before punishing them]. He has great strength to bear His anger and not avenge immediately. So Moshe said "Yigdal 1 Na Ko'ach Hashem; ? Hashem Erech Apayim" (Bamidbar 14:17-18). Malbim ? a person cannot delay anger, for he lacks strength to bear, and he fears that later he will not have strength to punish, for his strength is not forever.
Radak: Here "u'Gdal" is written with a Vov, but pronounced with Kamatz Chataf under the Dalet, for the first syllable of the coming word is accented.
What do we learn from "v'Nake Lo Yenake"?
Radak: Even though He delays His anger at Resha'im, like He did to Malchei Ashur, in the end He took His vengeance against them. Malbim ? He takes vengeance when their measure for sin is full. Hashem delayed His anger against Ninveh from when Yonah prophesized about it. Even though they repented only from theft in their hands, but not from idolatry, He did not punish them then. For idolatry, denial and denying Emunah 1 , He waits until their measure is full ? it was not full until now. Only for theft He wanted to eradicate them immediately, in 40 days.
The city believed Hashem's prophecy via Yonah! Perhaps they denied fundamentals of Emunah, e.g. that there is only one Power, He knows everything? (PF)
What is the meaning of "b'Sufah uvi'S'arah Darko"?
Rashi: Winds and storms are His messengers to exact payment from Oyvav, e.g. "b'Ru'ach Kadim Azah" (Shemos 14:21) and from Dor ha'Mabul "mi'Nishmas Eloka Yovedu [ume'Ru'ach Apo Yichlu]" (Iyov 4:9). It says about Tzor "Ru'ach Kadim Shevarech" (Yechezkel 27:27).
Radak: When He comes against Oyvav to destroy them, He comes quickly, in a moment, just like a wind and storm come quickly.
Malbim: Now the Navi explains three levels of how Hashem is revealed to punish Resha'im. (a) Via the the four elements (earth, fire, wind and water). He descends from above to destroy the land. The verse depicts that two elements, wind and water, accompany Him. Sometimes they destroy the land ? a storm wind can uproot mountains and break rocks, or a stream of clouds and flood of water.
Why does it say "v'Anan Avak Raglav"?
Rashi: Also this is the way of His vengeance ? "va'Yashkef Hashem El Machaneh Mitzrayim b'Amud Esh v'Anan" (Shemos 14:24), "Hi Anan Yechasenah" (Yechezkel 30:18).
Radak: This is darkness, like "va'Yhi he'Anan veha'Choshech" (Shemos 14:20). "Avak Raglav" are decrees that He makes against the enemies ? they are thick darkness for them. They are compared to dust that falls under the feet.
Malbim: Hashem rides on a fast cloud (Yesod ha'Mayim) to descend to destroy the land. It is as if via going quickly, His feet raise dust (a cloud).
