Musannaf Ibn Abi Shayba 9:1732

Abu Bakr narrated to us, he said: Isma'il ibn 'Ulayyah narrated to us, from Layth, from Mudrik, from Ibn Abi Awfa, he said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The adulterer does not commit adultery while he is a believer."