Sahih al-Bukhari 6098

'Abdu'r-Rahman ibn Abi Layla related that Ka'b ibn 'Ujra said, "I went to him,' i.e. the Prophet, may Allah bless him and grant him peace, 'and he said, 'Come near,' so I went near and he asked, 'Are your lice troubling you?' 'Yes,' I answered. He said, 'The fidya is fasting, sadaqa or offering a sacrifice." It is related that Ayyub said, "It is fasting three days, sacrificing a sheep or feeding six poor people." I. When is expiation obliged for rich and poor? The words of Allah, "Allah has made the expiation of your oaths obligatory for you. Allah is your Master. He is the All-Knowing, the All-Wise." (66:2)