Muslim Manners

Jabir (may Allah be pleased with him) reported:

Messenger of Allah, Muhammad (may Allah’s peace be upon him), said:

“When a morsel of any of you falls, he should pick it up and remove any of the dirt on it and then eat it, and should not leave it for Satan nor should 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.”

[Muslim]

Partial commentary from Riyad-us-Saliheen:  This Hadith tells us to pick up a fallen morsel and eat it after cleaning the dirt that may have stuck on it.  This marks the expression of humility overcoming Satan as well as getting the blessing…
[Riyad-us-Saliheen; Chapter 109, #751.  Dar-us-Salaam]