Musnad Ahmad Hadith 18120

Abdullah bin Ma’qil (may Allah have mercy on him) says that once I was present in the service of Ka’b bin ‘Ujrah (may Allah be pleased with him) who was in the mosque, and I asked him about this verse: "He should give a ransom, that is, fast or give charity or offer a sacrifice." He said: This verse was revealed concerning me. I had pain in my head and I was presented before the Prophet (peace and blessings of Allah be upon him), and at that time lice were falling on my face. The Prophet (peace and blessings of Allah be upon him) said: I did not think that your pain would reach this extent. Do you have a goat? I said: No. At that moment, this verse was revealed: "And whoever among you is ill or has an ailment of the head, then he should pay a ransom by fasting or giving charity or offering a sacrifice." That is, he should fast for three days or feed six needy people, half a sa’ of wheat to each. This verse was specific to my incident and general for you. It is narrated from Ka’b bin ‘Ujrah (may Allah be pleased with him) that this verse of ransom was revealed concerning me. The previous hadith is also narrated from this second chain.