Yazid bin Ibrahim narrated that I heard Imam Hasan al-Basri, may Allah have mercy on him, say about the person who does not fast during the days of Ramadan: He must offer expiation by freeing a slave, or slaughtering a camel, or giving twenty sa’ (approximately 45 kilograms) of grain to forty needy people. And the same expiation is obligatory upon the person who has intercourse with his wife while she is menstruating.