Al-Kāfi - Volume 3 > Brushing One’s Teeth
Hadith #3

3ـ أَحْمَدُ بْنُ مُحَمَّدٍ عَنِ ابْنِ مَحْبُوبٍ عَنِ الْعَلاَءِ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِي جَعْفَرٍ (عَلَيْهِ الْسَّلام) قَالَ قَالَ النَّبِيُّ (صلّى اللهُ عَلَيْهِ وَآلِه) مَا زَالَ جَبْرَئِيلُ (عَلَيْهِم الْسَّلام) يُوصِينِي بِالسِّوَاكِ حَتَّى خِفْتُ أَنْ أُحْفِيَ أَوْ أَدْرَدَ.

3. Ahmad ibn Muhammad has narrated from ibn Mahbub form al-‘Ala’ from Muhammad ibn Muslim who has said the following: “Abu Ja‘far, ‘Alayhi al-Salam, has said, ‘The Holy prophet has said, “Jibril continued urging me to brush my teeth, until I became fearful of the falling off of my teeth.’””