It is narrated by the Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, from Ahmad ibn Muhammad, from his father, from Sa’d ibn Abdullah, from Ahmad ibn Muhammad, from Al-Hasan ibn Ali Al-Washsha’, from Abdullah ibn Sinan, from Hafs, from Muhammad ibn Muslim, who said: I asked Imam عليه السلام about a man who had intercourse with his wife while she was menstruating. Imam عليه السلام said: 'He should give charity of one dinar and seek forgiveness from Allah سبحانه وتعالى, the Exalted.'"