What grace do they request?
Radak #1: In the days of Chizkiyah residents of Yerushalayim feared Melech Ashur; they needed to pray and request mercy.
Radak #2: If this is in the days of Mashi'ach, they fear Gog and Magog, and request mercy.
Malbim: Grace us even though we are not worthy based on our deeds. You should save us because "Lecha Kivinu."
What is the request "Heyeh Zero'am"?
Rashi: Be the arm of the plundered in the hand of the plunderer 1 . Radak - even though it says Chanenu in first person [plural], it says "Zero'am" in third person. Verses often do so, e.g. "Shim'u Amim Kulam" (Melachim I, 22:28).
Malbim: Be light Zaru'a (seeded) for the 10 tribes - now it is dark for them; they are in Galus.
I.e. wage the battle of the plundered against his afflicter. (PF)
What is "la'Bekarim"?
Rashi: Every day, when he afflicts them - so our salvation will be at a time of affliction.
Radak: Every morning.
Malbim: It is at the time of morning, i.e. redemption.
Why does it say "Af Yeshu'asenu b'Es Tzarah"?
Radak: [Be our arm every morning,] and all the more so at a time of affliction we will be saved via You!
Malbim: For us (in Yerushalayim), do not wait for morning to save us. Save us immediately at the time of affliction (when we are besieged)!
