Harith bin Hisham asked the Messenger of Allah ﷺ, "How does the revelation come to you?"He replied, "Sometimes it comes to me like the ringing of a bell, then it leaves me after I have grasped what was said. This is the hardest form for me. At other times it comes to me in the likeness of a young man who casts it to me."
أخبرنا إسحق بن إبراهيم قال أنبأنا سفيان عن هشام بن عروة عن أبيه
سأل الحارث بن هشام رسول الله ﷺ كيف يأتيك الوحي قال في مثل صلصلة الجرس فيفصم عني وقد وعيت عنه وهو أشده علي وأحيانا يأتيني في مثل صورة الفتى فينبذه إلي
Muslim narrated it in the Book of Virtues, Chapter on the Sweat of the Prophet ﷺ in Cold Weather and When Revelation Came to Him, no. 87/2333, from the hadith of Sufyan bin Uyayna, and Bukhari, no. 2, from the hadith of Hisham with the same wording. It is also found in Al-Kubra, no. 1005.