Hadith 3:95
Abu Umama reported God’s messenger as saying, “Gabriel never came to me without ordering me to use the tooth-stick, with the result that I have been afraid of chafing the front of my mouth.” Ahmad transmitted it.
وَعَنْ أَبِي أُمَامَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «مَا جَاءَنِي جِبْرِيلُ عَلَيْهِ السَّلَامُ قَطُّ إِلَّا أَمَرَنِي بِالسِّوَاكِ لَقَدْ خَشِيتُ أَنْ أُحْفِيَ مُقَدِّمَ فِيَّ» . رَوَاهُ أَحْمَدُ
Original Reference: Mishkat al-Masabih 386