1)
Why did he say "u'Mah Yacholti Asos Kachem"? He already said (verse 2) "Mah Asisi Atah Kachem"!
1.
Rashi: What could I do that would be as important as your act?
2.
Malbim: Your act showed more Gevurah than mine; it is attributed to Hashem ("b'Yedchem Nasan Elokim"); I could not do so.
2)
What is "Rucham"?
1.
Radak: It is their spirit of anger, like "Al Tevahel b'Ruchachah Lich'os" (Koheles 8:3).
