Abu Salama bin 'Abdur Rahman أبو سلمة بن عبد الرحمن بن عوف · The Book on Food

That the Prophet (ﷺ) said: "When one of you eats food, and he drops a pieces of it, then let him remove anything suspicious from it and eat it. Do not leave it for Ash-Shaitan." He said: There is something about this from Anas.

"When the Prophet (ﷺ) ate, he would lick his three fingers, and he said: 'If one of you drops a piece (of food) then let him remove any harm (dirt) from it and eat it, and do not leave it for Ash-Shaitan.' And he would order us to finish (clean) the dish. And he said: 'Indeed you do not know in which part of your food is the blessing.' This Hadith is Hasan Gharib Sahih.