From Sahih Bukhari (Hadith 1937):
Narrated Abu Huraira:A man came to the Prophet (ﷺ) and said, "I had sexual intercourse with my wife on Ramadan (while fasting)." The Prophet (ﷺ) asked him, "Can you afford to manumit a slave?" He replied in the negative. The Prophet (ﷺ) asked him, "Can you fast for two successive months?" He replied in the negative. He asked him, "Can you afford to feed sixty poor persons?" He replied in the negative. (Abu Huraira added): Then a basket full of dates was brought to the Prophet (ﷺ) and he said (to that man), "Feed (poor people) with this by way of atonement." He said, "(Should I feed it) to poorer people than we? There is no poorer house than ours between its (Medina's) mountains." The Prophet (ﷺ) said, "Then feed your family with it
Reference: Bukhari 1937