Al-Kāfi - The Book of Food

َّدٍ رَفَعَهُ قَالَ كَانَ أَ٠ِنِينَ ( عليه السلا٠) يَسْتَاكُ عَرْضاً وَ يَأْكُلُ هَرْتاً وَ قَالَ الْهَرْتُ أَنْ يَأْكُلَ بِأَصَابِعِهِ جَ٠5.

Ali ibn Muhammad in a marfu‘ manner has said the following: “’Amir al-Mu’minin (a.s.), would brush his teeth widthwise and eat using all of his fingers.’” رفوع - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (2/113))