Musnad Abu Ya'la al-Mawsili 106:68

Muhammad narrated to us, Muhammad narrated to us, Shu'bah narrated to us, from Abu Ishaq, that he heard al-Bara' ibn 'Azib saying: The Messenger of Allah (may Allah bless him and grant him peace) commanded a man, when he took to his bed, to 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, and I have leaned my back upon You, out of desire and fear of You. There is no refuge and no escape from You except to You. I have believed in Your Book which You revealed, and in Your Prophet whom You sent." For if he dies, he dies upon the natural disposition (fitrah).