Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
darimi:2077 – Mūsá b. Khālid > ʿĪsá b. Yūnus > Hishām b. ʿUrwah > ʿAbd al-Raḥman b. Saʿd al-Madanī > ʿAbdullāh b. Kaʿb or ʿAbd al-Raḥman b. Kaʿb Shak Hishām from his father

[Machine] "The Prophet ﷺ used to eat with his three fingers, and when he finished, he would lick them." Hisham also pointed with his three fingers.  

الدارمي:٢٠٧٧ – حَدَّثَنَا مُوسَى بْنُ خَالِدٍ حَدَّثَنَا عِيسَى بْنُ يُونُسَ عَنْ هِشَامِ بْنِ عُرْوَةَ عَنْ عَبْدِ الرَّحْمَنِ بْنِ سَعْدٍ الْمَدَنِيِّ أَنَّ عَبْدَ اللَّهِ بْنَ كَعْبٍ أَوْ عَبْدَ الرَّحْمَنِ بْنَ كَعْبٍ شَكَّ هِشَامٌ أَخْبَرَهُ عَنْ أَبِيهِ

«أَنَّ النَّبِيَّ ﷺ كَانَ يَأْكُلُ بِأَصَابِعِهِ الثَّلَاثِ فَإِذَا فَرَغَ لَعِقَهَا» وَأَشَارَ هِشَامٌ بِأَصَابِعِهِ الثَّلَاثِ  

See similar narrations below:

Collected by Muslim
muslim:2032c – Muḥammad b. ʿAbdullāh b. Numayr from my father > Hishām > ʿAbd al-Raḥman b. Saʿd > ʿAbd al-Raḥman b. Kaʿb b. Mālik or ʿAbdullāh b. Kaʿb > Abīh Kaʿb

'Abdullah b. Ka'b reported that his father Ka'b narrated to him that Messenger of Allah ﷺ used to eat with three fingers and when he had finished (eating), he licked them.  

مسلم:٢٠٣٢c – وَحَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ حَدَّثَنَا أَبِي حَدَّثَنَا هِشَامٌ عَنْ عَبْدِ الرَّحْمَنِ بْنِ سَعْدٍ أَنَّ عَبْدَ الرَّحْمَنِ بْنَ كَعْبِ بْنِ مَالِكٍ أَوْ عَبْدَ اللَّهِ بْنَ كَعْبٍ أَخْبَرَهُ عَنْ أَبِيهِ كَعْبٍ أَنَّهُ حَدَّثَهُمْ

أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَأْكُلُ بِثَلاَثِ أَصَابِعَ فَإِذَا فَرَغَ لَعِقَهَا