The Messenger of Allah ﷺ used to pray two units of prayer during the night, then he would finish and use the tooth-stick.
كان رسول الله ﷺ يصلي بالليل ركعتين، ثم ينصرف فيستاك.
Ibn Majah (288), Ahmad (1881), and Hakim (1/145) all narrated it through Ittham bin Ali Amiri, who said, Amash narrated to us, from Habib bin Abu Thabit, from Saeed bin Jubayr, from Ibn Abbas who said, and he mentioned it, the wording being Ahmad's. Nasai mentioned after it Ittham's statement, meaning two units of prayer before Fajr. Its chain of transmission is sahih, and Hakim said, "Sahih according to the criteria of the two Shaykhs."