Why does it say "v'Hirbah"?
Rashi: Many times (He diverted His anger).
Radak: Much Gevurah of the heart and increasing the power of mercy is needed to turn back anger - "v'Atah Yigdal Na Ko'ach Hashem" (Bamidbar 14:17).
What is the meaning of "Lehashiv Apo"?
Rashi: He diverted His anger from them. Even if He paid up from them, He did not arouse all His anger against them, only a little.
What is the difference between "Af" and "Chemah"?
Malbim: Af is external anger that punishes. Chemah is inner anger guarded in the heart. The external anger already went out and the plague began. Hashem in His great mercy turned away His Af, and did not arouse His Chemah at all. When Chemah joins with Af, it is impossible to turn it away - "Ki Yagorti Mipnei ha'Af veha'Chemah Asher Katzaf Hashem Aleichem Lehashmid Eschem" (Devarim 9:19).
