رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 237
The Book of Miscellany
Reverence towards the Sanctity of the Muslims
وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: “انْصُرْ أَخَاكَ ظَالِمًا أَوْ مَظْلُومًا” فَقَالَ رَجُلٌ: يَا رَسُولَ اللَّهِ أَنْصُرُهُ إِذَا كَانَ مَظْلُومًا أرأيت إن كَانَ ظَالِمًا كَيْفَ أَنْصُرُهُ؟ قَالَ: "تَحْجُزُهُ -أَوْ تَمْنَعُهُ- مِنَ الظُّلْمِ فَإِنَّ ذَلِكَ نَصْرُهُ” ((رَوَاهُ الْبُخَارِيّ)).
Anas (May Allah bepleased with him) reported: Messenger of Allah (ﷺ) said, "Help your brother, whether he is an oppressor or is oppressed". A man enquired: "O Messenger of Allah! I help him when he is oppressed, but how can I help him when he is an oppressor?" He (ﷺ) said, "You can keep him from committing oppression. That will be your help to him". [Al-Bukhari].
Riyad as-Salihin, 237