“Mayim Achronim” (literally meaning “last waters”) is a ritual that is performed at the conclusion of a meal to remove any salt from the fingers. We sprinkle salt on our bread to emphasize the similarity between the table at which we eat and the altar of Temple times. The Bible states “And with all your meat-offerings you shall offer salt” (Leviticus 2:13). Salt reminds us of the sin-offerings. The Hebrew word machal (“to forgive”) is composed of the same letters as melach (salt), as is bread, the foundation of the meal.
In ancient times, there was a danger that after a meal people might become drowsy and rub their eyes with their fingers. The Melach Sedomit (salt-extract from a bedrock) that was used in those days might have stuck to the fingers of the people during the meal and been rubbed into their eyes, blinding them. In modern times, even if there is no longer any health risk, most religious authorities hold that Mayim Achronim is a rabbinical dictum; as there is no physical blindness, so too should there not be a spiritual blindness. Salt reminds us that the poor should be welcomed guests at a Jewish table. Now that we have concluded our meal and are satisfied, we should not be “blind” to the poor who are hungry. According to the midrash, the people of Sedom were severely punished for their lack of hospitality by being turned into blocks of salt.