Riyad as-SalihinChapter 2Hadith 71
Full Sharh — Riyad as-Salihin 71
وعنه أن رسول الله صلى الله عليه وسلم قال: "إذا وقعت لقمة أحدكم، فليأخذها فليمط ما كان بها من أذى وليأكلها، ولا يدعها للشيطان، ولا يمسح يده بالمنديل حتى يلعق أصابعه؛ فإنه لا يدرى في أي طعامه البركة" .((رواه مسلم))
English Translation
Jabir (May Allah be pleased with him) reported:: The Messenger of Allah (ﷺ) 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.".
Source
Riyad as-Salihin(رياض الصالحين)
The Book About the Etiquette of Eating
Hadith Number
71