Sahih Muslim 5297
صحيح مسلم#5297SahihIbn Ka'b b. Malik reported on the authority of his father that the Messenger of Allah (ﷺ) used to eat (food) with three fingers and he licked his hand before wiping it (with towel)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 36:171