Musannaf Ibn Abi Shayba 17:1218

Sufyan ibn 'Uyaynah narrated to us, from Abu Ishaq, from al-Bara', who said: When the Prophet, may Allah bless him and grant him peace, would take to his bed, he would say: "O Allah, to You I have submitted my soul, and to You I have directed my face, and to You I have entrusted my affair, and to You I have leaned my back, 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" — or "Your Messenger whom You sent."