Musnad Ahmad 1153:2349

Husayn narrated to us, he said: Shayban narrated to us, from Mansur, from Hilal ibn Yasaf, from Farwah ibn Nawfal, that he said: I asked Aisha, I said: "Inform me of something that the Messenger of Allah, peace and blessings of Allah be upon him, used to supplicate with, so that I may supplicate to Allah with it, and Allah may benefit me through it." She said: The Messenger of Allah, peace and blessings of Allah be upon him, 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."