Musar על פסחים 132:5

And Chazal have said (Pesachim 66b): "Any man that gets angry — even if greatness has been decreed for him [by Heaven], he is brought down [from that greatness]. "and Chazal have said further (Nedarim 22a): "Whoever gets angry — all kinds of Gehinnom prevail over him." The intent is that for each [kind of] sin in itself there is, in Gehinnom, a distinct punishment for that sin. And through the trait of anger a man comes to all the different kinds of sin [as is clear] to one who reflects upon the evil of that trait, to the extent that Chazal have said about him that of a certainty his sins are more abundant that his merits. This is the intent of "All kinds of Gehinnom prevail over him." Therefore, a man must remove anger from his heart and he will be saved from Gehinnom and will merit life in the world to come.