عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ عَنْ رَجُلٍ مِنْ أَصْحَابِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ قَالَ رَجُلٌ يَا رَسُولَ اللَّهِ أَوْصِنِي قَالَ ((لَا تَغْضَبْ)) قَالَ قَالَ الرَّجُلُ فَفَكَّرْتُ حِينَ قَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ مَا قَالَ فَإِذَا الْغَضَبُ يَجْمَعُ الشَّرَّ كُلَّهُ
A companion of the Messenger narrates that a man said: O Messenger of Allah! Advise me. The Prophet (peace and blessings be upon him) said: Do not become angry. That man said: When I reflected upon the saying of the Messenger of Allah (peace and blessings be upon him), I concluded that anger encompasses all evil.