Musnad Abu Ya'la al-Mawsili 155:83

Abu Hammam narrated to us, Abd al-Rahim narrated to us, from Muhammad ibn Amr, from Abu Salamah, from Abu Hurayrah, who said: The companions of the Prophet (may Allah bless him and grant him peace) said: "O Messenger of Allah, we find within ourselves something that we would not like to speak of, even if we were to have what the sun rises upon." He said: "Have you indeed found that?" They said: "Yes." He said: "That is clear faith."