It is narrated from Sayyiduna Zayd bin Thabit (may Allah be pleased with him); he said: I was sitting at the side of the Messenger of Allah (peace and blessings be upon him) when the sakinah (the state of revelation) came over him (peace and blessings be upon him), and the thigh of the Messenger of Allah (peace and blessings be upon him) fell upon my thigh. I never felt anything heavier than the weight of the thigh of the Messenger of Allah (peace and blessings be upon him). Then, when that state passed, he (peace and blessings be upon him) said: "Write." So I wrote on a shoulder blade: "Not equal are those of the believers who sit (at home) and those who strive in the way of Allah" [Surah al-Nisa: 95] , to the end of the verse. When Sayyiduna Ibn Umm Maktum (may Allah be pleased with him), who was blind, heard of the virtue of the mujahidin, he stood up and said: O Messenger of Allah, what of those believers who are not able to wage jihad? When he had finished speaking, the sakinah came over the Messenger of Allah (peace and blessings be upon him) again, and his (peace and blessings be upon him) thigh fell upon my thigh, and the second time I felt the same weight that I had felt the first time. Then, when that state passed from him (peace and blessings be upon him), he (peace and blessings be upon him) said: "O Zayd, read." I read: "Not equal are those of the believers who sit (at home)," and the Messenger of Allah (peace and blessings be upon him) said: "Except those who are disabled" (and then completed the whole verse). Sayyiduna Zayd (may Allah be pleased with him) said: Allah Almighty revealed these words separately, so I attached them to the earlier words. By the One in whose Hand is my soul! It is as if I am still looking at those attached words beside the crack in the shoulder blade. This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.