(a) Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) reported: I spent a night at the house of my maternal aunt, the Mother of the Believers Sayyidah Maymunah (may Allah be pleased with her). I lay across the width of the pillow, and the Messenger of Allah (peace and blessings be upon him) and his wife lay along its length. The Messenger of Allah (peace and blessings be upon him) slept, and when it was midnight, or a little before or after it, the Messenger of Allah (peace and blessings be upon him) woke up and began rubbing the sleep from his face with his hand. Then he recited the last ten verses of Surah Al Imran, then went to a hanging water-skin and performed ablution from it thoroughly, then stood and prayed. And he mentioned the rest of the hadith.
(b) Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: I saw him (peace and blessings be upon him) stand up and use the miswak, then perform ablution while he was reciting these verses: "Indeed, in the creation of the heavens and the earth and the alternation of night and day are signs for those of understanding" [Surah Al Imran: 190], until he completed the surah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 420