Zayd bin Thabit reported,

Zayd bin Thabit said, I was sitting beside the Messenger of Allah ﷺ when the state of revelation came over him, and his thigh fell upon my thigh. I never felt anything heavier than the thigh of the Messenger of Allah ﷺ. Then it passed from him, and he said, "Write."So I wrote on a shoulder blade, "Not equal are those believers who remain behind and those who strive in the way of Allah" to the end of the verse.Then Ibn Umm Maktum stood up, and he was a blind man, when he heard of the excellence of those who strive, and he said, "Messenger of Allah, what about those among the believers who are unable to take part in jihad?"When he finished speaking, the state of revelation came over the Messenger of Allah ﷺ again, and his thigh fell upon my thigh, and I felt its weight the second time just as I had felt it the first time. Then it passed from the Messenger of Allah ﷺ, and he said, "Recite, Zayd."So I recited, "Not equal are those believers who remain behind," and the Messenger of Allah ﷺ said, "except those who are disabled," the whole verse.Zayd said, So Allah sent it down on its own, and I attached it. By Him in whose hand is my soul, it is as though I can still see the place where I attached it, beside a crack in the shoulder blade.

عن زيد بن ثابت قال

كنت إلى جنب رسول الله ﷺ فغشيته السكينة، فوقعت فخذ رسول الله ﷺ على فخذي، فما وجدت ثقل شيء أثقل من فخذ رسول الله ﷺ، ثم سرى عنه فقال: اكتب. فكتبت في كتف: {لا يستوي القعدون من المؤمنين والجهدون في سبيل الله} إلى آخر الآية. فقام ابن أم مكتوم،- وكان رجلا أعمى- لما سمع فضيلة المجاهدين فقال: يا رسول الله فكيف بمن لا يستطيع الجهاد من المؤمنين، فلما قضى كلامه شيت رسول الله ﷺ السكينة، فوقعت فخذه على فخذي، ووجدت من ثقلها في المرة الثانية كما وجدت في المرة الأولى، ثم سرى عن رسول الله ﷺ فقال: اقرأ يا زيد. فقرأت: {لا يستوي القاعدون من المؤمنين} فقال رسول الله ﷺ {غير أولي الضرر} الآية كلها. قال زيد: فأنزلها الله وحدها، فألحقتها، والذي نفسي بيده، لكأني أنظر إلى ملحقها عند صدع في كتف.