I sat with Kaab bin Ujra in the masjid and asked him about this verse, "then a fidya of fasting, or charity, or a sacrifice" [Baqarah 2:196].Kaab said, "It was revealed about me. I had an ailment in my head, and I was carried to the Messenger of Allah ﷺ with the lice scattering over my face.He said, 'I did not think the hardship had reached you to the extent that I now see. Can you find a sheep?'I said, 'No.'Then this verse was revealed, "then a fidya of fasting, or charity, or a sacrifice" [Baqarah 2:196]."He said, "The fasting is three days, the charity is to six poor people, half a measure of food for each poor person, and the sacrifice is a sheep."
حدثنا محمد بن بشار ومحمد بن الوليد قالا حدثنا محمد بن جعفر حدثنا شعبة عن عبد الرحمن بن الأصبهاني
قعدت إلى كعب بن عجرة في المسجد فسألته عن هذه الآية {ففدية من صيام أو صدقة أو نسك} قال كعب في أنزلت كان بي أذى من رأسي فحملت إلى رسول الله ﷺ والقمل يتناثر على وجهي فقال ما كنت أرى الجهد بلغ بك ما أرى أتجد شاة قلت لا قال فنزلت هذه الآية {ففدية من صيام أو صدقة أو نسك} قال فالصوم ثلاثة أيام والصدقة على ستة مساكين لكل مسكين نصف صاع من طعام والنسك شاة
Bukhari transmitted it in the book of the one prevented from completing Hajj, chapter on feeding as fidya, half a saa, hadith 1816, 4517, from the hadith of Shubah through this chain. Muslim also transmitted it in the book of Hajj, chapter on the permissibility of shaving the head for one in a state of ihram if he has an ailment, and the obligation of fidya for shaving it and an explanation of its amount, 12/1201, 85, from Muhammad bin Bashshar through this chain.