The Messenger of Allah ﷺ said, "When a morsel of food falls from one of you, let him pick it up, remove whatever dirt is on it, and eat it. He should not leave it for Satan. And he should not wipe his hand with a napkin until he has licked his fingers, for he does not know in which part of his food the blessing lies."In their version of the hadith it reads, "And he should not wipe his hand with a napkin until he has licked it," or "until he has had it licked," along with what follows.
و حدثناه إسحق بن إبراهيم أخبرنا أبو داود الحفري ح و حدثنيه محمد بن رافع حدثنا عبد الرزاق كلاهما عن سفيان بهذا الإسناد مثله وفي حديثهما ولا يمسح يده بالمنديل حتى يلعقها أو يلعقها وما بعده