Section 1 Mishkat al-Masabih 4164
Arabic hadith text
وَعَنْ كَعْبِ بْنِ مَالِكٍ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَأْكُلُ بِثَلَاثَةِ أَصَابِعَ وَيَلْعَقُ يَدَهُ قَبْلَ أَن يمسحها. رَوَاهُ مُسلم
Translation
Ka'b b. Malik said that God's messenger used to eat with three fingers and lick his hand before wiping it. Muslim transmitted it.