Anger is useless, and one who repeatedly succumbs to his anger brings on himself lack of focus, confusion, and dread.

At the moment one grows angry, even the Divine Presence is not important to him….

Rabbi Yirmeya of Difti said: He forgets his learning and adds foolishness….

Rav Nahman bar Yitzhak said: It is clear that his sins are more numerous than his merits, as it is stated: “And a man of fury abounds in transgression” (Proverbs 29:22).

Reish Lakish said: In the case of any person who grows angry, if he is a wise man, his wisdom departs from him; if he is a prophet, his prophecy departs from him.

Elijah the prophet said to Rav Yehuda brother of Rav Sala Hasida: Do not get angry and you will not sin.

Bar Kappara taught: An irritable person has succeeded only in acquiring the irritability. (Nedarim 22b; Pesaĥim 66b; Berakhot 29b; Kiddushin 40b–41a)