Why does it say "Hashem Ramah Yadecha"?
Rashi, citing Yalkut Shimoni 500: This is a Tefilah, that Nochrim should not see the good of Yisrael [when Mashi'ach comes; He 1 answered, it is better that they see, and be ashamed.
Rashi: Hashem, the hand of Your Gevurah was taken off Your afflicters. They will not see Your Gevurah, for they saw their way succeeding. I request that they see, and be ashamed amidst envy of [Your] nation, i.e. the good that You will bestow on them. They themselves should see the judgment of Your vengeance - "fire will consume them."
Radak: The Resha'im do not see when Your hand is lifted. I.e. when the punishment comes on the Resha'im, they do not think that it is from You.
Malbim: I have an answer why Resha'im are not punished immediately - in order to leave room for choice. If Hashem punished immediately, people would fear to do evil, and they would be forced in their actions - "Asher Ein Na'asah Pisgam Ma'aseh ha'Ra'ah Meherah Al Ken Malei Lev Bnei ha'Adam Bahem La'asos Ra" (Koheles 8:11). Your hand (Mishpat) is raised, so they do not see and there is room to do good or evil - "v'Tzadikim Yelchu Vam u'Fosh'im Yikashlu Vam" (Hoshe'a 14:10).
In our text, Moshe said so. Rashi - the verse implies unlike the Midrash. "Ramah" is not a request! Also, every Yad Ramah in Tanach, the accent is on the last syllable (the Mem). Here, it is on the Reish; it is past tense, like "Kamah Alumasi" (Bereishis 37:7), "Shavah Yevimtech" (Rus 1:15).
What is the meaning of "Yechezu v'Yevoshu Kin'as Am"?
Rashi: Refer to 26:11:1:2.
Radak: They should see at the time of salvation, when You will have Kin'ah for Your nation. They will see and be ashamed. This is like "Kineisi li'Yrushalayim Kin'ah Gedolah" (Zecharyah 1:14). Then, they will not be able to say 'it is chance'! They will see a small nation saved from great nations; then, they will be embarrassed.
Malbim: I know that Hashem does not punish immediately, to leave room for choice. I say that it would be better that they see and be ashamed of their deeds; they already filled their measure of sin. There are two reasons to punish now. (a) Kin'as Am - You should have Kin'ah for what they did to Your Am. (a) Refer to 25:11:3:2.
Which fire will consume them?
Radak: When a person is ashamed, his face turns to fire - "Pnei Lehavim Pneihem" (13:8).
Malbim: It is proper that the fire that they themselves lit, it will consume them.