[Machine] I used to write down the revelation in the presence of the Messenger of Allah, ﷺ . He would feel intense pressure and sweat profusely, as if pearls were falling from him. Then, it would ease off from him and I would write while he dictated to me. I would not stop until I felt heavy. When I had finished, he would say, "Read it." So, I would read it to him, and if there was any mistake, he would correct it.  

كُنْتُ أَكْتُبُ الْوَحْيَ عِنْدَ رَسُولِ اللهِ ﷺ وَكَانَ يَشْتَدُّ نَفَسَهُ ويَعْرَقُ عَرَقًا شَدِيدًا مِثْلَ الْجُمَانِ ثُمَّ يُسَرَّى عَنْهُ فَأَكْتُبُ وَهُوَ يُمْلِي عَلَيَّ فَمَا أَفْرَغُ حَتَّى يَثْقُلَ فَإِذَا فَرَغْتُ قَالَ «اقْرَأْ» فَأَقْرَأَهُ فَإِنْ كَانَ فِيهِ سَقْطٌ أَقَامَهُ