Sahih Muslim Book 003, Hadith Number 0685.
Chapter : Abrogation of (the command that) bath is obligatory(only) because of seminal emission and instead contact of the circumcised parts makes bath obligatory.
'Aisha the wife of the Apostle of Allah (may peace be upon him) reported. A person asked the Messenger of Allah (may peace be upon him) about one who has sexual intercourse with his wife and parts away (without orgasm) whether bathing is obligatory for him. 'Aisha was sitting by him. The Messenger of Allah (may peace be upon him) said: I and she (the Mother of the Faithful) do it and then take a bath.