Musnad Ahmad 30:2913

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, from Sa'd ibn Ibrahim, he said: I heard Humayd ibn 'Abd al-Rahman narrating from Abu Hurayrah, from the Prophet, may Allah bless him and grant him peace, that he said: "It is not fitting for a servant to say: 'I am better than Yunus ibn Matta.'"