It was narrated that Ibn 'Abbas said:
"The Messenger of Allah used to pray in the night (Qiyamul-Lail) two Rak'ah by two, then when he finished he would use the tooth stick." (DE)
English reference (DE): Vol. 1, Book 1, Hadith 288 (DE)
Arabic reference (DE): Book 1, Hadith 303 (DE)