Jamiat Tirmidhi: Hadith 3620

Every night, when the Prophet (ﷺ) would go to his bed, he would join his hands, then blow in them, as he recited in them: “Say: He is Allah, the One.” And “Say: I seek refuge in the Lord of Al-Falaq” and “Say: I seek refuge in the Lord of mankind.” Then he would wipe as much as he was able to of his body with them, beginning with them first of his head and face, and the front of his body. He would do this three times.