Allah Most High says:
And those who swallow anger those who forgive people, Allah loves the righteous (Quran 3:134).
The Messenger of Allah (Allah bless him and give him peace) said:
Do not become angry (Bukhari).
A strong man is not one who defeats (another) in physical combat. Verily, a strong man is he who controls his self at the time of anger (Bukhari, Muslim).
In another narration it is said that a strong man is he who controls anger. It is essential to keep anger under control. One should never act spontaneously in order with dictates of anger. On the contrary, anger should be made subservient to the commands of the Shari`a. It is natural to be aroused in the state of anger. Such natural propensity is not blameworthy [in itself]. But Allah Most High has endowed man with willpower. Anger has therefore to be controlled since its within the scope of man’s willpower to do so. Failure to exercise this volitional power is contrary to human nature.
There are many reasons for the inclusion of anger in the natural attributes of man. Along with the quality of anger, Allah Most High has endowed man with the ability to control anger to ensure that it is not misdirected and unjustly employed. Anger in itself arises involuntarily. It is automatically activated. But acting in accordance with its demand is voluntary; hence, refraining from it likewise voluntary. The remedy for a non-volitional act (the way of curbing it) is nothing other than the exercise of one’s willpower in order to bring about restraint and control. This is within one’s ability even if one experiences a degree of difficulty in exercising willpower. Repeated exercise of the will weakens the demands of anger. In consequence, refraining from anger becomes a relatively simple task.
The following narration appears in the noble hadith: “A judge should not decide between two parties while angry” (Bukhari, Abu Dawud). The judge or ruler is not permitted to issue a verdict while angry, but should postpone the trial for a later date. The term judge in the context of this hadith applies to every person with authority over people. The instructor, teacher and head of a family all fall within the scope of this hadith. They should not hasten to mete out punishment upon their subordinates while angry.
Those is authority should remember that Allah Most High is the defender of the rights of those who have no defender. Allah Most High will demand from the aggressor the rights of the oppressed. According to the noble hadith, Allah Most High and the Messenger of Allah (Allah bless him and give him peace) will claim from the tyrannical ruler the rights he usurped even from his non-Muslim subjects. It is therefore imperative to exercise caution when passing judgment.
In cases of injustice carried out in the state of anger, it is essential that the aggressor, after his anger has subsided, publicly apologize and humble himself in the presence of the one whom he has wronged. The aggressor should personally apologize in profusion and seek the pardon of the one he wronged. This measure will restore the anger of the aggressor to equilibrium. He will thus be prevented from the perpetration of injustice at the behest of anger.
At all times, avoid haste. Strive seriously to oppose the dictates of anger. Whenever you succumb, resort to asking for forgiveness and obtain pardon of the one whose rights have been violated. Recite: A`udhu bi’Llahi mina’sh-Shaytani’ra-rajim, “I seek refuge in Allah from Satan the accursed.”
When overcome by anger, sit down if you happen to be standing , lay down if sitting. Perform ablution with cold water or drink cold water. Divert your attention by immediately engaging in some other activity, especially reading with is very effective in curbing anger. If all this fails to eliminate anger, withdraw from the presence of the one who is the object of your anger.
Remember that Allah Most High has greater power and authority over you and that you are disobedient to Him. If he adopts the attitude of wrath toward you, where will you be then? Also reflect that nothing can happen without the will of Allah. Ponder then, of what worth am I? I am an absolute nonentity. How can I then act in conflict with Allah Most High?
(The Path to Perfection, Shaykh Maseehullah Khan)