The Messenger of Allah ﷺ said, "When a morsel of food falls from one of your hands, let him wipe off whatever has stuck to it and eat it."
حدثنا علي بن المنذر حدثنا محمد بن فضيل حدثنا الأعمش عن أبي سفيان
قال رسول الله ﷺ إذا وقعت اللقمة من يد أحدكم فليمسح ما عليها من الأذى وليأكلها
No references are available.
Muslim narrated it in the Book of Foods, Chapter on the Recommendation of Licking the Fingers and the Bowl and Eating a Fallen Morsel after Wiping Off Whatever Dirt Has Gotten on It, etc., hadith no. 2033/135, from the hadith of Ibn Fudayl through this same chain.