What is the meaning of "ha'Ya'amod Libech"?
Radak: Can your heart stand during the many afflictions that I bring upon you, i.e. the days of the afflictions?
Malbim: Had the decree been due to sins Bein Adam la'Makom, Teshuvah could have fixed it. However, it was for sins Bein Adam l'Chavero. Teshuvah does not help until he returns the theft. If so, how will your heart stand in the days that I bring you to judgment?
What do we learn from "Ani Oseh Osach"?
Rashi: I will do to you like your actions.
Why does it say "Dibarti v'Asisi"?
Radak: Like I spoke, so will I fulfill, for "Ani Hashem" ? I have the ability.
Malbim: When I spoke the final verdict, the action was already done. One cannot undo what was already done.