Harith bin Hisham asked the Messenger of Allah ﷺ, "Messenger of Allah, how does the revelation come to you?"He replied, "Sometimes it comes to me like the ringing of a bell, and that is the hardest on me. It leaves me after I have grasped what was said. And sometimes the angel appears to me in the form of a man who speaks to me, and I retain what he says."Ayesha said, "I saw revelation descending upon him on a bitterly cold day, and when it left him, his forehead was streaming with sweat."
أن الحارث بن هشام سأل رسول الله ﷺ فقال: يا رسول الله! كيف يأتيك الوحي؟ فقال: أحيانا يأتيني مثل صلصلة الجرس وهو أشد علي، فيفصم عني وقد وعيت عنه ما قال، وأحيانا يتمثل لي الملك رجلا فيكلفني فأعي ما يقول. قالت عائشة: ولقد رأيته ينزل عليه الوحي في اليوم الشديد البرد فيفصم عنه، وإن جبينه ليتفصد عرقا.
Malik narrated it in Kitab al-Quran (7) from Hisham bin Urwa, from his father, from Ayesha, and I have already mentioned it. Bukhari narrated it in Kitab Badi al-Wahi (2) through the route of Malik, with the same wording. Muslim narrated it in Kitab al-Fadail (2333) through other routes from Hisham bin Urwa, and Muslim's wording is similar to it, with Ayesha's statement in it being, "The revelation would sometimes come down upon the Messenger of Allah ﷺ on a cold morning, and then his forehead would stream with sweat."As for his phrase, "fa-yafsim," with a fatha on the first letter, a saakin fa, and a kasra on the sin, it means, it lifts and what has been overwhelming me becomes clear.