Anger is considered one of the most destructive traits. Yaakov Avinu (Jacob) strongly admonishes his children Shimon and Levi: "Accursed is their rage for it is intense, and their wrath for it is harsh..." Shlomo Hamelech (King Solomon) warns: "Anger resides in the bosom of fools." The Midrash criticizes Moshe for becoming angry: "Rabbi Eliezer states: in three instances (Moshe) came to be angry and thus came to err: Upon being angry at Elazar and Itamar the sons of Aharon; after being angry with the commanding soldiers who returned from battle with Midian; and upon being angry at the Children of Israel when they demanded water." (Aside from the destructive nature of becoming angry, I think that it’s helpful to also consider that “For every minute you are angry you lose sixty seconds of happiness” R.W. Emerson.)
It is puzzling that "anger" is so destructive and is nevertheless not the subject of a direct commandment. There is no mitzvah: "Thou shalt not be angry." Rav Chaim Vital in his classic work "Sha'arei Kedusha" addresses this question, and answers it with a very profound concept. Before we ever get to the point of performing mitzvahs there is a need to develop our basic character. The traits that comprise our character determine the way in which we fulfill the mitzvahs. We must spend our energy in perfecting these aspects of ourselves — once these are properly developed we can perform the mitzvahs with relative ease.
In conclusion: Overcoming anger is a foundation for the proper fulfillment of the entire Torah, and is therefore not counted as a separate mitzvah.
