Sahih Bukhari Volume 007, Book 064, Hadith Number 281.
Narrated By Abu Huraira : A man came to the Prophet and said, "I am ruined!" The Prophet said, "Why?" He said, "I had sexual intercourse with my wife while fasting (in the month of Ramadan)." The Prophet said to him, "Manumit a slave (as expiation)." He replied, "I cannot afford that." The Prophet said, "Then fast for two successive months." He said, "I cannot." The Prophet said, "Then feed sixty poor persons." He said, "I have nothing to do that." In the meantime a basket full of dates was brought to the Prophet. He said, "Where is the questioner." The man said, "I am here." The Prophet said (to him), "Give this (basket of dates) in charity (as expiation)." He said, "O Allah's Apostle! Shall I give it to poorer people than us? By Him Who sent you with the Truth, there is no family between Medina's two mountains poorer than us." The Prophet smiled till his pre-molar teeth became visible. He then said, "Then take it."