Musannaf Ibn Abi Shayba 37:327

Ishaq ibn Mansur narrated to us, he said: Asbat ibn Nasr narrated to us, from al-Suddi, from his father, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A believer does not commit treachery (fatk) while he has faith; treachery is a restraint (qayd) upon faith."