Musannaf Ibn Abi Shayba 1:1791

'Affan narrated to us, he said: Hammam narrated to us, he said: 'Ali ibn Zayd ibn Jud'an narrated to me, he said: Muhammad narrated to me, from 'Aishah, that the Prophet, may Allah bless him and grant him peace, would not sleep, neither by night nor by day, and then wake up, except that he would use the toothstick (siwak) before he performed ablution.