Mukhtasar Muslim

`Sayyiduna Abu Musa (may Allah be pleased with him) said that` a group of the Muhajirun and Ansar differed regarding this issue (the obligation of ghusl). The Ansar said that ghusl becomes obligatory only when semen spurts out and ejaculation occurs, while the Muhajirun said that ghusl becomes obligatory when a man has intercourse with a woman. Sayyiduna Abu Musa (may Allah be pleased with him) said, "I will satisfy you regarding this." I got up and went to the house of Umm al-Mu'minin Aisha Siddiqa (may Allah be pleased with her) and sought permission from her. When she granted permission, I said, "O Umm al-Mu'minin, I want to ask you something, but I feel shy." Umm al-Mu'minin Aisha Siddiqa (may Allah be pleased with her) said, "Do not feel shy to ask about something which you could ask your real mother who gave birth to you. I am also your mother (because the wives of the Messenger of Allah, peace and blessings be upon him, are the mothers of the believers)." I said, "From what does ghusl become obligatory?" She said, "You have asked a knowledgeable person. The Messenger of Allah (peace and blessings be upon him) said: 'When a man sits between the four parts of a woman and the circumcised parts meet (i.e., the penis enters the vagina), then ghusl becomes obligatory.'"