Sahih Bukhari Volume 003, Book 031, Hadith Number 157.
Narated By Abu Huraira : While we were sitting with the Prophet a man came and said, "O Allah's Apostle! I have been ruined." Allah's Apostle asked what was the matter with him. He replied "I had sexual intercourse with my wife while I was fasting." Allah's Apostle asked him, "Can you afford to manumit a slave?" He replied in the negative. Allah's Apostle asked him, "Can you fast for two successive months?" He replied in the negative. The Prophet asked him, "Can you afford to feed sixty poor persons?" He replied in the negative. The Prophet kept silent and while we were in that state, a big basket full of dates was brought to the Prophet. He asked, "Where is the questioner?" He replied, "I (am here)." The Prophet said (to him), "Take this (basket of dates) and give it in charity." The man said, "Should I give it to a person poorer than I? By Allah; there is no family between its (i.e. Medina's) two mountains who are poorer than I." The Prophet smiled till his pre-molar teeth became visible and then said, 'Feed your family with it."