عَنْ ابْنِ كَعْبِ بْنِ مَالِكٍ، عَنْ أَبِيهِ: أَنّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَأْكُلُ بِثَلَاثِ أَصَابِعَ، وَلَا يَمْسَحُ يَدَهُ حَتَّى يَلْعَقَهَا (ابو داؤد:۳۸۴۸)
Translation
Hazrat Ka'b bin Malik (may Allah be pleased with him) narrated that the Prophet (peace and blessings of Allah be upon him) used to eat with three fingers, and he (peace and blessings of Allah be upon him) would not wipe his hand until he (peace and blessings of Allah be upon him) had licked it. (Abu Dawud - Translated)