"Not equal are those believers who sit at home and those who strive in the cause of Allah", the Messenger of Allah ﷺ ordered Zayd, who brought a shoulder-blade bone to write it down. Then Ibn Umm Maktum complained of his blindness, so the verse was revealed, "Not equal are those believers who sit at home, other than those who have a disability" [Nisa 4:95].
لا يستوي القاعدون من المؤمنين والمجاهدون في سبيل الله فأمر رسول الله ﷺ زيدا، فجاء بكتف يكتبها، فشكا ابن أم مكتوم ضرارته فنزلت: {لا يستوي القاعدون من المؤمنين غير أولي الضرر}. [سورة النساء: ٩٥].
Bukhari related it in Jihad and Expeditions (2831), and Muslim in Leadership (1898:141), both through the route of Shubah, from Abu Ishaq, who said, I heard Bara say, and then he mentioned it. The wording given is Muslim's.Bukhari also related it in the Virtues of the Quran (4990) from Ubaydullah bin Musa, from Israil, from Abu Ishaq, from Bara, who said, When "Those believers who sit at home, other than the disabled, are not equal to those who strive in the cause of Allah" was revealed, the Prophet ﷺ said, "Call Zayd for me, and let him bring the tablet, the inkpot, and the shoulder bone, or the shoulder bone and the inkpot." Then he said, "Write, 'Those who sit at home are not equal.'" Behind the back of the Prophet ﷺ was Amr bin Umm Maktum, the blind man, who said, "O Messenger of Allah, what do you command me to do, for I am a man of impaired sight?" So in its place there was revealed, "Those believers who sit at home are not equal to those who strive in the cause of Allah, other than the disabled."However, there occurred here a transposition, for his words "other than the disabled" are connected to his words "those who sit at home among the believers are not equal," because the verse reads thus, "Those believers who sit at home, other than the disabled, are not equal to those who strive in the cause of Allah" [Nisa 4:95].As for his word "the shoulder bone," it refers to the bone.