Kalb bin Ujra (RA) reported: It was I for whom this verse was revealed (to the Holy Prophet): "Whoever among you is sick or has an ailment of the head, he (may effect) a compensation by fasting or alms or a sacrifice" He said: I came to him (the Holy Prophet) and he said: Come near. So I went near. He (again) said: Come near. So I went near. Thereupon the Messenger of Allah ( صلی اللہ علیہ وسلم ) said: Do the vermins trouble you? Ibn Aun (one of the narrators) said: I think he (Ka'b bin Ujra) replied in the affirmative. He (the Holy Prophet) then commanded to do compensation by fasting or by giving sadaqa (feeding six needy persons) or by sacrifice (of a animal) that is available.