1)
What is the meaning of "Al Dami Lach"?
1.
Rashi: Do not be quiet to the evil that our enemies do to us.
2.
Radak: Do not be quiet at this time of affliction.
3.
Malbim: Do not be quiet and abandon Your deeds. You used to save Yisrael until now!
2)
Why does it say "Al Techerash v'Al Tishkot"?
1.
Malbim: Charishah is the opposite of a verbal answer. You need to answer, for the matter pertains to You, like will be explained. Hashkatah is not answering in deed.