Sahih Muslim Book 35, Hadith Number 6546.
Chapter : Supplication at the time of sleeping and going to bed.
Al-Bara’ b. ‘Azib reported that Allah’s Messenger (in may peace be upon him) commanded a person (in these words): When you go to bed during night, you should say: “O Allah, I surrender myself to Thee and entrust my affair to Thee, with hope in Thee and fear of Thee. There is no resort and no deliverer (from hardship but Thou). I affirm my faith in the Book which Thou revealed and in the Messengers whom Thou sent.” If you die in this state you would die on Fitra, and Ibn Bashshdr did not make a mention of “night” in this hadith.