From Sahih Bukhari (Hadith 4593):
Narrated Al-Bara:When the Verse:-- "Not equal are those of the believers who sit (at home)" (4.95) was revealed, Allah's Apostle called for Zaid who wrote it. In the meantime Ibn Um Maktum came and complained of his blindness, so Allah revealed: "Except those who are disabled (by injury or are blind or lame..." etc)
Reference: Bukhari 4593