Sahih Bukhari | Volume 8 | Hadith Number 323

Narrated by Al-Bara bin 'Azib
Allah's Apostle said to me, "When you want to go to bed, perform ablution as you do for prayer, then lie down on your right side and say: 'Allahumma aslamtu wajhi ilaika, wa fauwadtu Amri ilaika wa aljatu zahri ilaika, raghbatan wa rahbatan ilaika, lamalja'a wa la manja mink a ill a ilaika. Amantu bikitabi kalladhi anzalta wa bi nabiyyikal-ladhi arsalta'. If you should die then (after reciting this) you will die on the religion of Islam (i.e., as a Muslim); so let these words be the last you say (before going to bed)" While I was memorizing it, I said, "Wa birasiulikal-ladhi arsalta (in Your Apostle whom You have sent).' The Prophet said, "No, but say: Wa binabiyyi-kalladhi arsalta (in Your Prophet whom You have sent)."