Al-Adab Al-Mufrad #1213

Abu Hurayra said, "The Messenger of Allah, may Allah bless him and grant him peace, said, 'When one of you goes to bed, he should undo the inside of his lower garment and dust the bed with it. He does not know what has come on his bed since he left it. He should lie down on his right side and say, 'In Your Name I have laid down on my side. If You take my soul, then have mercy on it. If You release it, then preserve it in the manner in which You preserve the men of right action."