Hadith 8:13
Sahih (Al-Albani)
He reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "Who do you reckon to be the one who most often throws people down (in a fight)?" They replied, "The one whom men do not throw down." He said, "No the one who throws people down is the person who controls himself when he is angry."
قَالَ: وَقَالَ رَسُولُ اللهِ صلى الله عليه وسلم: مَا تَعُدُّونَ فِيكُمُ الصُّرَعَةَ؟ قَالُوا: هُوَ الَّذِي لاَ تَصْرَعُهُ الرِّجَالُ، فَقَالَ: لاَ، وَلَكِنَّ الصُّرَعَةَ الَّذِي يَمْلِكُ نَفْسَهُ عِنْدَ الْغَضَبِ
Original Reference: Al-Adab Al-Mufrad 155