Hafsa said that when God’s messenger wanted to go to sleep he put his right hand under his cheek, and would then say three times, "O God, guard me from Thy punishment on the day when Thou raisest up Thy servants." Abu Dawud transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب الدعوات / 2402
Hadith Gradingالألبانی:لم تتمّ دراسته | زبیر علی زئی:إسناده حسن
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «إسناده حسن، رواه أبو داود (5045)»