Musnad Abu Ya'la al-Mawsili 150:185

Abu Kurayb narrated to us, Mu'awiyah ibn Hisham narrated to us, from 'Imran ibn Abi Anas al-Makki, from Ibn Abi Mulaykah, from 'Aishah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said to his companions: "Do you know what is the most adulterous of adultery in the sight of Allah?" They said: "Allah and His Messenger know best." He said: "Indeed, the most adulterous of adultery in the sight of Allah is the making lawful of the honor of a Muslim man." Then he recited: "And those who harm believing men and believing women for [something] other than what they have earned" (Al-Ahzab: 58).