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." (AR)
English reference (AR): Vol. 1, Book 1, Hadith 288 (AR)
Arabic reference (AR): Book 1, Hadith 303 (AR)