Whenever the Prophet ﷺ went to his bed each night, he would cup his hands together, breathe into them, and recite into them "Say, He is Allah, the One" [Ikhlas 112:1], "Say, I seek refuge with the Lord of the daybreak" [Falaq 113:1], and "Say, I seek refuge with the Lord of mankind" [Nas 114:1]. Then he would wipe with them whatever he could reach of his body, beginning with his head and his face and the front of his body. He would do this three times.
أن النبى ﷺ كان إذا أوى إلى فراشه كل ليلة جمع كفيه ثم نفث فيهما، فقرأ فيهما {قل هو الله أحد} [الإخلاص: ١] {قل أعوذ برب الفلق} [الفلق: ١] {قل أعوذ برب الناس} [الناس: ١] ثم يمسح بهما ما استطاع من جسده، يبدأ بهما على رأسه ووجهه، وما أقبل من جسده يفعل ذلك ثلاث مرات.