1)
What "Madon" does he arouse?
1.
Rashi: It is Midas ha'Din.
2.
Malbim: Af is external anger. An Ish Af, who does not have internal anger, and he wants to harm his colleague, he arouses Madon - claims against him, so he will have the right to harm him.
2)
What do we learn from "u'Va'al Chemah Rav Pesha"?
1.
Nedarim 22b: An angry person, clearly, his sins outnumber his merits.
2.
Malbim: Chemah is internal anger. One who has inner anger, he does not seek a veil to justify himself. He does evil without any Din (pretext).