Musnad Abu Ya'la al-Mawsili 105:24

Then he said: "Shall I not teach you words that are better than them?"—as if he were attributing them to the Prophet, may Allah bless him and grant him peace—he said: "When you take to your bed at night, say: 'O Allah, I have submitted my soul to You, and I have turned my face toward You, and I have entrusted my affair to You. I believe in Your Book which You revealed and Your Prophet whom You sent. Indeed, my soul is a soul You created for Yourself; its life is for You and its death is for You. So if You take it, have mercy upon it, and if You delay it, protect it with the protection of faith.'"