Ibn 'Abbas reported Allah's Messenger (may peace be upon him.) as saying:When any one of you eats food he should not wipe his hand until he has licked it or has it licked
Ibn Ka'b b. Malik reported on the authority of his father that he saw Allah's Messenger (ﷺ) licking his three fingers (after having finished the food). Ibn Hatim made no mention of" three". This hadith is also narrated through another chain of transmitters
Hadith 5297 — Sahih Muslim 36:171
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو مُعَاوِيَةَ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ عَبْدِ الرَّحْمَنِ، بْنِ سَعْدٍ عَنِ ابْنِ كَعْبِ بْنِ مَالِكٍ، عَنْ أَبِيهِ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَأْكُلُ بِثَلاَثِ أَصَابِعَ وَيَلْعَقُ يَدَهُ قَبْلَ أَنْ يَمْسَحَهَا .
Ibn Ka'b b. Malik reported on the authority of his father that the Messenger of Allah (ﷺ) used to eat (food) with three fingers and he licked his hand before wiping it (with towel)
Abdullah b. Ka'b reported that his father Ka'b narrated to him that Allah's Messenger (ﷺ) used to eat with three fingers and when he had finished (eating), he licked them
Hadith 5299 — Sahih Muslim 36:173
وَحَدَّثَنَاهُ أَبُو كُرَيْبٍ، حَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا هِشَامٌ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ سَعْدٍ، أَنَّحَدَّثَاهُ - أَوْ، أَحَدُهُمَا - عَنْ أَبِيهِ، كَعْبِ بْنِ مَالِكٍ عَنِ النَّبِيِّ صلى الله عليه وسلم بِمِثْلِهِ .
A hadith like this has been reported on the authority of Ka'b b. Malik through another chain of transmitters
Hadith 5300 — Sahih Muslim 36:174
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم أَمَرَ بِلَعْقِ الأَصَابِعِ وَالصَّحْفَةِ وَقَالَ " إِنَّكُمْ لاَ تَدْرُونَ فِي أَيِّهِ الْبَرَكَةُ " .
Jabir reported that Allah's Messenger (ﷺ) commanded the licking of fingers and the dish, saying:You do not know in what portion the blessing lies
Jabir reported Allah's Messenger (ﷺ) as saying:When any one of you drops a mouthful he should pick it up and remove any of the filth on it, and then eat it, and should not leave it for the Satan, and should not wipe his hand with towel until he has licked his fingers, for he does not know in what portion of the food the blessing lies
Jabir reported:I heard Allah's Apostle (ﷺ) as saying: The Satan is present with any one of you in everything he does; he is present even when he eats food; so if any one of you drops a mouthful he should remove away anything filthy on it and eat it and not leave for the devil; and when he finishes (food) he should lick his fingers, for he does not know in what portion of his food the blessing lies