Mukhtasar Muslim

Umm al-Mu’minin Aisha Siddiqa (may Allah be pleased with her) says that revelation would descend upon the Messenger of Allah (peace and blessings be upon him) even during cold days, and due to the intensity of the revelation, sweat would pour from his forehead.

Narrated from Umm al-Mu’minin Aisha Siddiqa (may Allah be pleased with her) that Harith bin Hisham asked the Messenger of Allah (peace and blessings be upon him), “How does revelation come to you?” The Messenger of Allah (peace and blessings be upon him) replied, “Sometimes it comes to me like the ringing of a bell, and that is the hardest for me. Then when it ends, I remember what was said. And sometimes an angel comes to me in the form of a man, and I remember what he says.”