It is narrated from Sayyiduna Zayd bin Thabit (may Allah be pleased with him); he said: I used to write (the revelation) for the Messenger of Allah (peace and blessings be upon him), and one day I had placed the pen on my ear when the command to fight (jihad) was revealed. Just then a blind man came and said: "What is the ruling concerning me, when I am deprived of sight?" Then this verse was revealed: "There is no blame upon the blind" [Surah al-Fath: 17].
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4907