Remembrance 6 from Chapter 60
What to say when one intends to sleep and is lying in bed
Allāhumma innī aslamtu nafsī ilayk, wa fawwaḍtu amrī ilayk, wa alja’tu ẓahrī ilayk, raghbatan wa rahbatan ilayk, lā malja’a wa lā manjā minka illā ilayk, āmantu bi-Kitābika-lladhī anzalt, wa Nabiyyika-lladhī arsalt.
We relate in the two Ṣaḥīḥs, from al-Barā’ ibn ‘Āzib 
who reported that Allah’s Messenger 
told him: “When you go to bed, perform ablution as you would for ṣalāh, then lie down on your right side and recite: O Allah, I submit my soul to You, and I entrust my destiny to You. I retreat unto You for protection, with hope in You and fear of You. There is no refuge and no safety from You but with You. I affirm my faith in Your Book, which You revealed, and Your Messenger, whom You sent. If you pass away that night, you will die in the true religion. Make these the last words that you say.” [9].This is the wording of one of al-Bukhārī’s versions, whereas the rest of the narration is Muslim’s version, which is very similar.