Musnad Ahmad 1153:667

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, from Husayn, from Hilal ibn Yasaf, from Farwah ibn Nawfal, he said: I said to 'Aishah: Inform me of a supplication that the Messenger of Allah, peace and blessings of Allah be upon him, used to supplicate with. She said: He used to frequently say: "O Allah, I seek refuge in You from the evil of what I have done, and from the evil of what I have not done."