حَدَّثَنَا الْحَسَنُ بْنُ أَبِي عَلِيٍّ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنِ ابْنِ جُرَيْجٍ، حَدَّثَنِي عِمْرَانُ بْنُ مُوسَى، عَنْ سَعِيدِ بْنِ أَبِي سَعِيدٍ الْمَقْبُرِيِّ، يُحَدِّثُ عَنْ أَبِيهِ، أَنَّهُ رَأَى أَبَا رَافِعٍ مَوْلَى النَّبِيِّ صلى الله عليه وسلم مَرَّ بِحَسَنِ بْنِ عَلِيٍّ عَلَيْهِمَا السَّلاَمُ وَهُوَ يُصَلِّي قَائِمًا وَقَدْ غَرَزَ ضُفُرَهُ فِي قَفَاهُ فَحَلَّهَا أَبُو رَافِعٍ فَالْتَفَتَ حَسَنٌ إِلَيْهِ مُغْضَبًا فَقَالَ أَبُو رَافِعٍ أَقْبِلْ عَلَى صَلاَتِكَ وَلاَ تَغْضَبْ فَإِنِّي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ذَلِكَ كِفْلُ الشَّيْطَانِ ‏"‏ ‏.‏ يَعْنِي مَقْعَدَ الشَّيْطَانِ يَعْنِي مَغْرِزَ ضُفُرِهِ

Narrated AbuRafi'

Sa'id ibn Abu Sa'id al-Maqburi reported on the authority of his father that he saw Abu Rafi', the freed slave of the Prophet (ﷺ), passing by Hasan ibn Ali (may peace be upon them both) while he was standing and praying, and he had tucked his braided hair behind his neck (or gathered it at the back of his head), so Abu Rafi' untied it. Hasan turned to him angrily, and Abu Rafi' said to him, "Focus on your prayer and do not be angry, for I heard the Messenger of Allah (ﷺ) saying: 'That is the portion of the Satan'" — meaning the seat of the Satan, meaning the place where hair is gathered at the back of the neck.