Narrated Zaid bin Thabit: That the Prophet dictated to him: "Not equal are those of the believers who sit (at home) and those who strive and fight in the Cause of Allah." Zaid added: Ibn Um Maktum came while the Prophet was dictating to me and said, "O Allah's Apostle! By Allah, if I had the power to fight (in Allah's Cause), I would," and he was a blind man. So Allah revealed to his Apostle while his thigh was on my thigh, and his thigh became so heavy that I was afraid it might fracture my thigh. Then that state of the Prophet passed and Allah revealed:-- "Except those who are disabled (by injury or are blind or lame etc).

Narrated Sahl bin Sa`d As-Sa`idi: I saw Marwan bin Al-Hakam sitting in the Mosque. So I came forward and sat by his side. He told us that Zaid bin Thabit had told him that Allah's Apostle had dictated to him the Divine Verse: "Not equal are those believers who sit (at home) and those who strive hard and fight in the Cause of Allah with their wealth and lives.' (4.95) Zaid said, "Ibn-Maktum came to the Prophet while he was dictating to me that very Verse. On that Ibn Um Maktum said, "O Allah's Apostle! If I had power, I would surely take part in Jihad." He was a blind man. So Allah sent down revelation to His Apostle while his thigh was on mine and it became so heavy for me that I feared that my thigh would be broken. Then that state of the Prophet was over after Allah revealed "...except those who are disabled (by injury or are blind or lame etc.) (4.95)