Sunan at-Tirmithiy كتاب الرضاع باب ما جاء فى كراهية إتيان النساء فى أدبارهن
A Bedouin came to the Prophet, peace and blessings of God be upon him and said, "Messenger of God, a man may happen to be in the desert and pass wind, and water is scarce." The Messenger of God, peace and blessings of God be upon him, said, “Anyone who passes wind must perform ablution, and do not be intimate with women from their behinds, for indeed, God does not shy away from the truth.” Click on ḥadīth to read more
The Messenger of God, peace and blessings of God be upon him said, “God does not look [with mercy] upon a man who is intimate with a man or a woman from the back passage.” Click on ḥadīth to read more