Musnad Ahmad #60

Abu Hurairah said: Abu Bakr said: O Messenger of Allah, tell me something I may say in the morning and in the evening. He said: `Say: 'O Allah, Knower of the unseen and the seen, Creator of the heavens and the earth, Lord and Sovereign of all things, I bear witness that there is no god but You, I seek refuge in You from the evil of my own self and the evil of the Shuitart and the shirk to which he calls.` And he told him to say it in the morning and in the evening and when going to bed.