Musnad Ahmad 1153:836

Yahya ibn Ghaylan narrated to us, he said: Al-Mufaddal narrated to us, he said: Aqil ibn Khalid al-Ayli narrated to me, from Ibn Shihab, from Urwah ibn al-Zubayr, from Aisha: "That the Prophet, peace and blessings of Allah be upon him, whenever he went to his bed every night, he would join his palms together, then blow into them, and recite into them: 'Say, He is Allah, [who is] One,' 'Say, I seek refuge in the Lord of daybreak,' and 'Say, I seek refuge in the Lord of mankind.' Then he would wipe with them whatever he could of his body, beginning with them upon his head, his face, and what faced him of his body. He would do that three times."