[Commentary]
The author—may Allah have mercy on him—relates, through the report of Jābir ibn ʿAbd Allah, one of the etiquettes of eating taught by the Prophet ﷺ. Among them is that when a person finishes his meal he should lick his fingers and lick the dish, that is, pass his tongue over them until no trace of food remains, for, as the Prophet said, “You do not know in which part of your food the blessing lies.” These are therefore two etiquettes: first, licking the dish; second, licking the fingers. The Prophet ﷺ never instructs his community to do anything unless it contains goodness and blessing.

For this reason physicians say that licking the fingers after eating yields a benefit: it makes digestion easier, because the fingertips—by Allah’s permission—secrete a substance during licking that aids the digestive process. We mention this only to show some of the wisdom behind the Sacred Law’s commands; our basic motive, however, is to comply with the order of the Prophet ﷺ. Many people do not grasp this sunnah: you see someone finish eating while food still clings to the rim of his plate, and he goes off to wash without first licking his fingers. Yet the Prophet ﷺ forbade a person to wipe his hands with a napkin until he has licked them clean of food; after that he may wipe with the napkin, and then wash if he wishes.

Another etiquette of eating is that if a morsel falls to the ground one should not leave it, for Satan attends a person in all his affairs—eating, drinking, marital relations, everything. If you do not mention Allah’s Name when you begin to eat, he shares your food and thereby the blessing is removed from it. But if you pronounce the Name of Allah over the food and then a morsel falls