Compiled by Imam Muslim ibn al-Hajjaj
حَدَّثَنَا أَحْمَدُ بْنُ عَبْدِ اللَّهِ بْنِ يُونُسَ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا أَبُو الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ اقْتَتَلَ غُلاَمَانِ غُلاَمٌ مِنَ الْمُهَاجِرِينَ وَغُلاَمٌ مِنَ الأَنْصَارِ فَنَادَى الْمُهَاجِرُ أَوِ الْمُهَاجِرُونَ يَا لَلْمُهَاجِرِينَ . وَنَادَى الأَنْصَارِيُّ يَا لَلأَنْصَارِ . فَخَرَجَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَقَالَ " مَا هَذَا دَعْوَى أَهْلِ الْجَاهِلِيَّةِ " . قَالُوا لاَ يَا رَسُولَ اللَّهِ إِلاَّ أَنَّ غُلاَمَيْنِ اقْتَتَلاَ فَكَسَعَ أَحَدُهُمَا الآخَرَ قَالَ " فَلاَ بَأْسَ وَلْيَنْصُرِ الرَّجُلُ أَخَاهُ ظَالِمًا أَوْ مَظْلُومًا إِنْ كَانَ ظَالِمًا فَلْيَنْهَهُ فَإِنَّهُ لَهُ نَصْرٌ وَإِنْ كَانَ مَظْلُومًا فَلْيَنْصُرْهُ " .
What is this, the proclamation of the days of jahiliya (ignorance)? They said: Allah's Messenger, there is nothing serious. The two young men fell into dispute and the one struck at the back of the other. Thereupon he (the Holy Prophet) said: Well, a person should help his brother whether he is an oppressor or an oppressed. If he is the oppressor he should prevent him from doing it, for that is his help; and if he is the oppressed he should be helped (against oppression).