the Messenger of Allah ﷺ said, "The strong is not the one who overcomes the people by his strength, but the strong is the one who controls himself while in anger."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ: «لَيْسَ الشَّدِيدُ بِالصُّرَعَةِ إِنَّمَا الشَّدِيدُ الَّذِي يَمْلِكُ نَفْسَهُ عِنْدَ الْغَضَبِ۔»  

Two men abused each other in front of the Prophet ﷺ while we were sitting with him. One of the two abused his companion furiously and his face became red. The Prophet ﷺ said, "I know a word (sentence) the saying of which will cause him to relax if this man says it. Only if he said, "I seek refuge with Allah from Satan, the outcast.' " So they said to that (furious) man, 'Don't you hear what the Prophet ﷺ is saying?" He said, "I am not mad."  

اسْتَبَّ رَجُلاَنِ عِنْدَ النَّبِيِّ ﷺ وَنَحْنُ عِنْدَهُ جُلُوسٌ وَأَحَدُهُمَا يَسُبُّ صَاحِبَهُ مُغْضَبًا قَدِ احْمَرَّ وَجْهُهُ فَقَالَ النَّبِيُّ ﷺ إِنِّي لأَعْلَمُ كَلِمَةً لَوْ قَالَهَا لَذَهَبَ عَنْهُ مَا يَجِدُ لَوْ قَالَ أَعُوذُ بِاللَّهِ مِنَ الشَّيْطَانِ الرَّجِيمِ فَقَالُوا لِلرَّجُلِ أَلاَ تَسْمَعُ مَا يَقُولُ النَّبِيُّ ﷺ قَالَ إِنِّي لَسْتُ بِمَجْنُونٍ  

A man said to the Prophet ﷺ, "Advise me! "The Prophet ﷺ said, "Do not become angry and furious." The man asked (the same) again and again, and the Prophet ﷺ said in each case, "Do not become angry and furious."  

أَنَّ رَجُلاً قَالَ لِلنَّبِيِّ ﷺ: أَوْصِنِي. قَالَ: «لاَ تَغْضَبْ۔» فَرَدَّدَ مِرَارًا قَالَ: «لاَ تَغْضَب۔»