كتاب الأشربة
36  
The Book of Drinks
(18)
Chapter: It is recommended to lick one's fingers and wipe the bowl, and to eat a piece of food that is dropped after removing any dirt on it. It is disliked to wipe one's hand before licking it, because of the possibility that the blessing of the food may be in that remaining part. The Sunnah is to eat with three fingers
(18)
باب اسْتِحْبَابِ لَعْقِ الأَصَابِعِ وَالْقَصْعَةِ وَأَكْلِ اللُّقْمَةِ السَّاقِطَةِ بَعْدَ مَسْحِ مَا يُصِيبُهَا مِنْ أَذًى وَكَرَاهَةِ مَسْحِ الْيَدِ قَبْلَ لَعْقِهَا
Sahih Muslim 2033 e

This hadith is reported on the authority of A'mash with the same chain of transmitters but with a slight variation of words but no mention is made of the first part of the hadith, i. e. the Satan is present with any one of you.

وَحَدَّثَنَاهُ أَبُو كُرَيْبٍ، وَإِسْحَاقُ بْنُ إِبْرَاهِيمَ، جَمِيعًا عَنْ أَبِي مُعَاوِيَةَ، عَنِ الأَعْمَشِ، بِهَذَا الإِسْنَادِ ‏"‏ إِذَا سَقَطَتْ لُقْمَةُ أَحَدِكُمْ ‏"‏ ‏.‏ إِلَى آخِرِ الْحَدِيثِ وَلَمْ يَذْكُرْ أَوَّلَ الْحَدِيثِ ‏"‏ إِنَّ الشَّيْطَانَ يَحْضُرُ أَحَدَكُمْ ‏"‏ ‏.‏
Reference : Sahih Muslim 2033e
In-book reference : Book 36, Hadith 178
USC-MSA web (English) reference : Book 23, Hadith 5047
  (deprecated numbering scheme)