What is the meaning of "Al Tisra Es Ba'al Af"?
Rashi: Do not join with him. Tisra is an expression of Re'us (camaraderie).
R. Yonah: Tisra has the same grammatical form as "Al Tis'av l'Mat'amosav" (23:3). This is like "va'Tehi
Why does it add "v'Es Ish Chemos Lo Savo"?
R. Yonah: Chemah is fiercer than Af. Chemah is when the Ru'ach overpowers in the heart due to anger, until it heats the body. We always find Chemah after Af - "b'Af uv'Chemah", "b'Apo uv'Chamaso" (Devarim 29:27, 22). Some people get mildly angry, and some get very angry; the latter is Ish Chemos. Do not go on the road with him. "Savo" is like "Orach b'Raglav Lo Yavo" (Yeshayah 41:3). One should make a fence to separate from his company, for great damage comes from it. Regarding a Ba'al Af, the verse warns only against being his friend, but not against traveling with him.
Malbim: A Ba'al Chemah bears hatred in his heart. He does not take vengeance immediately. This is worse. Do not go with him at all, even not due to friendship.
