Sahih al-Bukhari 3215

Farwa narrated to us: ʿAli ibn Mushir narrated to us, from Hisham ibn ʿUrwa, from his father, from ʿAʾisha (may Allah be pleased with her), that al-Harith ibn Hisham asked the Prophet (ﷺ), ‘How does revelation come to you?’ He said, ‘All these ways: sometimes the angel comes to me with a sound like the ringing of a bell. When it departs, I have retained what it said. This is the hardest form for me. Sometimes the angel appears to me as a man and speaks to me, and I retain what he says.’