Abu Dawud Book 1, Hadith Number 57.
Chapter : Using toothstick after getting up during the night.
Narated By Ibn Abbas : I spent a night with the Prophet (PBUH). When he woke up from his sleep (in the later part of the night for prayer) he came to his ablution water. He took the tooth-stick and used it. He then recited the verse: “Verily in the creation of the heavens and the earth and the alternation of the night and the day are tokens (of His Sovereignty) for men of understanding” (Quran iii. 190). He then recited these verses almost up-to the end of the chapter or he finished the whole chapter. He then performed ablution and came to the place of prayer. He then said two rak’ahs of prayer. He then lay down on the bed and slept as much as Allah wished. He then got up and did the same. He then lay down and slept. He then got up and did the same. Every time he used the tooth-stick and offered two rak’ahs of prayer. He then offered the prayer known as witr.
Abu Dawud said: Fudail on the Authority of Husain reported the wording: He then used the tooth-stick and performed ablution while he was reciting the verses: “Verily in the creation of the heavens and the earth…” until he finished the chapter.