RKC: Anger is not the word that should be used. This is the lesson to be learned in the life of Moses. Unlike the Bible, which has him committing premediated murder (Ex. 2:12), Moses killed a man by accident because of his temper…his anger. This is something Moses had to wage “jihad” against. Also, please see 7:154

Surah 28

15. And he entered the city at a time when its people were not watching: and he found there two men fighting,- one of his own religion, and the other, of his foes. Now the man of his own religion appealed to him against his foe, and Moses struck him with his fist and made an end of him. He said: "This is a work of Evil (Satan): for he is an enemy that manifestly misleads!"

16. He prayed: "O my Lord! I have indeed wronged my soul! Do Thou then forgive me!" So (Allah) forgave him: for He is the Oft-Forgiving, Most Merciful.

17. He said: "O my Lord! For that Thou hast bestowed Thy Grace on me, never shall I be a help to those who sin!"

Surah 7

154. When the anger of Moses was appeased, he took up the tablets: in the writing thereon was guidance and Mercy for such as fear their Lord.

Anger is something that is extrememly hard to control and should be restrained.

Surah 3

134. Those who spend (freely), whether in prosperity, or in adversity; who restrain anger, and pardon (all) men;- for Allah loves those who do good;-

Muhammad is the perfect example of this calm, even in the Battle of Badr.

Surah 9
26. But Allah did pour His calm on the Messenger and on the Believers, and sent down forces which ye saw not: He punished the Unbelievers; thus doth He reward those without Faith.

Muslims are to be calm, firm, patient whether they are in pain, adversity, or panic.

Surah 2

177. It is not righteousness that ye turn your faces Towards east or West; but it is righteousness- to believe in Allah and the Last Day, and the Angels, and the Book, and the Messengers; to spend of your substance, out of love for Him, for your kin, for orphans, for the needy, for the wayfarer, for those who ask, and for the ransom of slaves; to be steadfast in prayer, and practice regular charity; to fulfil the contracts which ye have made; and to be firm and patient, in pain (or suffering) and adversity, and throughout all periods of panic. Such are the people of truth, the Allah-fearing.