Anger is the reaction of adrenalin and speeding of the heart and the desire for vengeance or retribution. Anger for the sake of Allah is obligatory upon the Muslim. One who does not become angry at the violation of Allah's boundaries has a weakness in their faith. Anger for other than Allah is from Shaitaan. Sometimes these two meet when one defends their rights. It is in one sense for the self, but it is also standing up for the boundaries established by Allah. This is obviously a dangerous area and requires careful self-inspection to keep Shaitaan out of one's affairs.
فَمَا أُوتِيتُمْ مِنْ شَيْءٍ فَمَتَاعُ الْحَيَاةِ الدُّنْيَا وَمَا عِنْدَ اللَّهِ خَيْرٌ وَأَبْقَى لِلَّذِينَ آمَنُوا وَعَلَى رَبِّهِمْ يَتَوَكَّلُونَ (36) وَالَّذِينَ يَجْتَنِبُونَ كَبَائِرَ الْإِثْمِ وَالْفَوَاحِشَ وَإِذَا مَا غَضِبُوا هُمْ يَغْفِرُونَ (37) وَالَّذِينَ اسْتَجَابُوا لِرَبِّهِمْ وَأَقَامُوا الصَّلَاةَ وَأَمْرُهُمْ شُورَى بَيْنَهُمْ وَمِمَّا رَزَقْنَاهُمْ يُنْفِقُونَ (38) وَالَّذِينَ إِذَا أَصَابَهُمُ الْبَغْيُ هُمْ يَنْتَصِرُونَ (39) وَجَزَاءُ سَيِّئَةٍ سَيِّئَةٌ مِثْلُهَا فَمَنْ عَفَا وَأَصْلَحَ فَأَجْرُهُ عَلَى اللَّهِ إِنَّهُ لَا يُحِبُّ الظَّالِمِينَ (40) وَلَمَنِ انْتَصَرَ بَعْدَ ظُلْمِهِ فَأُولَئِكَ مَا عَلَيْهِمْ مِنْ سَبِيلٍ (41) إِنَّمَا السَّبِيلُ عَلَى الَّذِينَ يَظْلِمُونَ النَّاسَ وَيَبْغُونَ فِي الْأَرْضِ بِغَيْرِ الْحَقِّ أُولَئِكَ لَهُمْ عَذَابٌ أَلِيمٌ (42) وَلَمَنْ صَبَرَ وَغَفَرَ إِنَّ ذَلِكَ لَمِنْ عَزْمِ الْأُمُورِ (43) وَمَنْ يُضْلِلِ اللَّهُ فَمَا لَهُ مِنْ وَلِيٍّ مِنْ بَعْدِهِ وَتَرَى الظَّالِمِينَ لَمَّا رَأَوُا الْعَذَابَ يَقُولُونَ هَلْ إِلَى مَرَدٍّ مِنْ سَبِيلٍ (44)
Whatever ye are given (here) is (but) a convenience of this Life: but that which is with Allah is better and more lasting: (it is) for those who believe and put their trust in their Lord; (36) Those who avoid the greater crimes and shameful deeds, and, when they are angry even then forgive; (37) Those who hearken to their Lord, and establish regular prayer; who (conduct) their affairs by mutual Consultation; who spend out of what We bestow on them for Sustenance; (38) And those who, when an oppressive wrong is inflicted on them, (are not cowed but) help and defend themselves. (39) The recompense for an injury is an injury equal thereto (in degree): but if a person forgives and makes reconciliation, his reward is due from Allah: for (Allah) loveth not those who do wrong. (40) But indeed if any do help and defend themselves after a wrong (done) to them, against such there is no cause of blame. (41) The blame is only against those who oppress men with wrong-doing and insolently transgress beyond bounds through the land, defying right and justice: for such there will be a Penalty grievous. (42) But indeed if any show patience and forgive, that would truly be an exercise of courageous will and resolution in the conduct of affairs. (43) For any whom Allah leaves astray, there is no protector thereafter. And thou wilt see the wrong-doers, when in sight of the Penalty, say: "Is there any way (to effect) a return?" (44)
Ash-Shooraa: 36-44
(36) Since a large portion of conflict originates in matters relating to wealth, Allah reminds us that all that is in this earth is nothing but a temporary provision. Our primary focus should always be the far superior rizq of Allah which awaits those who make it to Paradise. Part of tawakkul: tafweedh al-amoor ilaa Allahi. Deferring one's issues/rights to Allah. The following verses discuss the virtues of these mutawakkileen - those who place their reliance wholly upon Allah and that the rewards or Paradise are "for them".
(37) Kabaa'iri al-ithmi: the major sins generally.
Al-Fawaahish: the worst or "obscene" among them such as fornication, murder.
Those who forgive the one who has transgressed upon them. Hadith sahih:
"Maa intaqama an-nabiyyu (sas) li nafsihi qattu, illa an yuntahaka hurumaati Allahi."
"The Prophet (sas) never ever avenged himself, rather only where the prohibitions of Allah had been transgressed."
Keeping away from sin and being of forgiving character are additional characteristics of the people of Paradise.
(38) Further description of the believers being talked abou here. They ANSWSER the call of Allah, responding with fulfilling the obligations and staying away from the prohibited. They maintain/establish the prayer. They work cooperatively together for the establishment of Allah's deen on this earth using consultation as their means of arriving at the best solution. They spend of their wealth in Allah's path.
(39) Allah has praised and even recommended forgiving and forgoing ones rights when they have been transgressed, but He did NOT order this. Rather, Allah praised among the attributes of the believers that they are "those who when transgressed upon achieve victory". Humiliation at the hands of transgressors is not one of the attributes of those whom Allah has described as "mighty" - {Wa lillahi al-'izzatu wa li rasoolihi wa lil-mu'mineen}. Rather, fighting for one's rights (or for what is right) is a noble character of a believer.
(40) This can only be in kind and not out of proportion with the original transgression. Allah has no love for oppressors. Nonetheless, if the transgressed-upon (especially after victory) forgives and forgoes, his reward is established with Allah.
(41) Justice is uppermost in Islam and even takes precedence over peace when that is what is required. If a party is transgressed upon and they strike back at their oppressor and restore their rights, there is nothing upon them and steps cannot be taken against them for that.
(42) Those against whom steps can be taken are those who oppress people and transgress in the land. Theirs will be a painful punishment in the hereafter even if they get away with it in this life.
(43) Whoever is patient and forbearing and forgives even when he has the right and the ability is in the best position of all.
مَنْ كَظَمَ غَيْظًا وَهُوَ يَسْتَطِيعُ أَنْ يُنَفِّذَهُ دَعَاهُ اللَّهُ يَوْمَ الْقِيَامَةِ عَلَى رُءُوسِ الْخَلَائِقِ حَتَّى يُخَيِّرَهُ فِي أَيِّ الْحُورِ شَاءَ قَالَ هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ (الترمذي)
True power, dignity and status in Islam come not from anger, noise and overpowering others physically, psychologically or politically. Rather, it comes from maturity, restraint, wisdom and forbearance.
قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَا تَعُدُّونَ الرَّقُوبَ فِيكُمْ قَالَ قُلْنَا الَّذِي لَا يُولَدُ لَهُ قَالَ لَيْسَ ذَاكَ بِالرَّقُوبِ وَلَكِنَّهُ الرَّجُلُ الَّذِي لَمْ يُقَدِّمْ مِنْ وَلَدِهِ شَيْئًا قَالَ فَمَا تَعُدُّونَ الصُّرَعَةَ فِيكُمْ قَالَ قُلْنَا الَّذِي لَا يَصْرَعُهُ الرِّجَالُ قَالَ لَيْسَ بِذَلِكَ وَلَكِنَّهُ الَّذِي يَمْلِكُ نَفْسَهُ عِنْدَ الْغَضَبِ
The Prophet (sas) said: "Do you know who is raqoob (one who has no children survive) among you?" They said, "The one with no children" He (sas) said, "That one is not raqoob rather it is the one of offers none of his sons." Then he (sas) said, "Who do you consider as-sura'a (champion, physically undefeated) among you?" They said, "The one who man cannot take down." He (sas) said, "That one is not as-sura'a, rather it is the one who has control of himself even when angry." (Muslim)
Once a Bedouin was rude to Umar (ra) in his office of khalifa. He came to him and said, "O Umar you do no justice in your rulings and no fairness in your divisions." Umar's face changed as he became angry and was about to do something to the bedouin. Then a man said, "O leader of the believers, do you now hear Allah's statement:
{... وَأَنْ تَعْفُوا أَقْرَبُ لِلتَّقْوَى وَلَا تَنْسَوُا الْفَضْلَ بَيْنَكُمْ إِنَّ اللَّهَ بِمَا تَعْمَلُونَ بَصِيرٌ (237) }
Whereupon Umar (ra) said, "You are right." And it was if a fire had blazed up and suddenly been extinguished.
Anger for other than Allah is from Shaitaan. Whoever experiences anger should question him/herself: Is this anger purely for Allah or for "me"? A Muslim should avoid anger, acting on anger and should seek refuge in Allah from Shaitaan when anger occurs.
Anger can cause a person to reject Allah's truth even though they know it to be the truth. Allah said:
{Bi'samaa ishtarau bihi anfusahum an yakfuroo bimaa anzala Allahu baghyan an yunazzila Allahu min fadhlihi 'alaa man yashaa'u min 'ibaadihi...} Al-Baqarah: 90
It even caused a Companion of Allah's Messenger (sas) to disrespect and disregard the words of Allah's Messenger (sas):
Two men insulted one another in the presence of Allah's Messenger (sas) and one of them became very angry. His face became red and swollen. The Prophet (sas) looked at him and said: "I know a word that were he to say it, that state he is in would leave him: I seek refuge in Allah from the accursed Shaitaan." So one man went to him and said: Do what Allah's Messenger has just said? He said: No. He said: "I know a word that were he to say it, that state he is in would leave him: I seek refuge in Allah from the accursed Shaitaan." The man said: So, do you think I am majnoon?! Muslim & Bukhari
So, beware of both: