He reported that he saw Abu Rafi, the freed slave of the Messenger of Allah ﷺ, pass by Hasan bin Ali while he was standing in prayer with his braid tucked up at the back of his neck. Abu Rafi undid it, and Hasan turned to him angrily.Abu Rafi said, "Attend to your prayer and do not be angry, for I heard the Messenger of Allah ﷺ say, 'That is a seat for Satan,'" meaning the place where the braid is tucked up.
حدثنا عبد الرزاق: حدثنا ابن جريجج حدثني عمران بن موسي
انه راي ابا رافع مولي رسول الله ﷺ مر بحسن بن علي و هو يصلي قائما، و قد غرز ضفيرته في قفاه، فحلها ابو رافع، فالتفت اليه مغضبا، فقال ابو رافع: اقبل علي صلاتك و لا تغضب، فاني سمعت رسول الله ﷺ يقول: ذلك كفل الشيطان. يعني مغرز ضفيرته.