GEN1347 We should be careful not to speak harshly even when angry.   The Midrash Genesis Rabbah 74:10 makes note of Yaakov’s self-control despite his anger.  Lovon accused Yaakov of stealing his idols. After Lovon had inspected all of Yaakov’s possessions and did not find anything, Yaakov felt that Lovon had fabricated the entire accusation (Sforno). But despite his anger, Yaakov did not say anything that would antagonize Lovon or stir up animosity and rancor.   He merely defended himself against accusation and restated his own innocence.  The Chofetz Chaim said that from here we learn that a person should avoid becoming involved in a dispute, even when he knows that he is in the right.   (Chofetz Chayim al Hatorah, on this verse).   PLYN 103-4