Mishkat al-Masabih, hadith 2313

وَعَنْ سُلَيْمَانَ بْنِ صُرَدَ قَالَ: اسْتَبَّ رَجُلَانِ عِنْدَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَنَحْنُ عِنْدَهُ جُلُوسٌ وَأَحَدُهُمَا يَسُبُّ صَاحِبَهُ مُغْضَبًا قَدِ احْمَرَّ وَجْهُهُ فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنِّي لَأَعْلَمُ كَلِمَةً لَوْ قَالَهَا لَذَهَبَ عَنْهُ مَا يَجِدُ أَعُوذُ بِاللَّهِ مِنَ الشَّيْطَانِ الرَّجِيمِ» . فَقَالُوا لِلرَّجُلِ: لَا تَسْمَعُ مَا يَقُولُ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ؟ قَالَ: إِنِّي لستُ بمجنون

Two men reviled one another in the Prophet’s presence when we were sitting near him, and when one of them who had become red in the face reviled the other angrily the Prophet said that he knew a phrase by repeating which the man could get rid of his angry feelings: “I seek refuge in God from that accursed devil.” Those present asked the man whether he heard what the Prophet was saying, and he replied, “I am not possessed by a devil.”* *Majnun. The word literally means to be possessed by a jinni, but it can also mean to be possessed by a devil. Shaitan is used in the preceding sentence. Majnun is also used meaning ‘mad’, but that does not fit this context. (Bukhari and Muslim.)