I saw the Prophet ﷺ licking his three fingers after eating.In another narration, the Messenger of Allah ﷺ used to eat with three fingers and would lick his hand before wiping it.
رأيت النبي ﷺ يلعق أصابعه الثلاث من الطعام. وفي رواية: كان رسول الله ﷺ يأكل بثلاث أصابع، ويلعق يده قبل أن يمسحها.
Muslim narrated it in the Book of Drinks (2032:131) through the route of Ibn Mahdi, from Sufyan, from Saad bin Ibrahim, from Ibn Kaab bin Malik, from his father, who said, and then he related it. In one of the narrations it reads, from Abdul-Rahman bin Kaab, from his father. As for the other narration, Muslim related it following the first narration, through the route of Hisham bin Urwa, from Abdul-Rahman bin Saad, from Ibn Kaab bin Malik, with the same wording.It is recommended to eat with three fingers if the food is solid, otherwise it is permissible to eat it with five fingers.