It is also narrated from Imam Awza'i, may Allah have mercy on him, regarding a man who has intercourse with his wife during her menstruation or after she becomes pure but before she performs ghusl (ritual bath), he said: That man should seek forgiveness from Allah and give one-fifth of a dinar in charity.
Hadith Referenceسنن دارمي / من كتاب الطهارة / 1152