Hudhaifa said that when the Prophet wanted to go to sleep he placed his hand under his head and said, "O God, guard me from thy punishment on the day when Thou gatherest Thy servants," or "raisest up Thy servants." Tirmidhi transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب الدعوات / 2400
Hadith Gradingالألبانی:لم تتمّ دراسته | زبیر علی زئی:صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «صحيح، رواه الترمذي (3398 وقال: حسن صحيح)»