Sahih Muslim , Book 32, Hadith 6313 (USC-MSA) ⓘ
Abu Huraira reported Allah's Messenger as saying: The strong-man is not one who wrestles well but the strong man is one who controls himself when he is in a fit of rage.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، وَعَبْدُ الأَعْلَى بْنُ حَمَّادٍ، قَالاَ كِلاَهُمَا قَرَأْتُ عَلَى مَالِكٍ عَنِ ابْنِ شِهَابٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لَيْسَ الشَّدِيدُ بِالصُّرَعَةِ إِنَّمَا الشَّدِيدُ الَّذِي يَمْلِكُ نَفْسَهُ عِنْدَ الْغَضَبِ " .
also referenced under: Book 45, Hadith 140 (In-Book) & Hadith 2609 (Reference)