Musar su Esodo 16:19

The absence of flies in the slaughterhouse cited as one of the ten miracles which occurred in the Holy Temple symbolises an absence of bodily desires. The body is less likely to decay when one controls them. Rabbi Akavyah therefore demanded an awareness of the fact that there would be a price to pay for indulging one's body in order to frighten us into controlling such urges. Berachot 10a states that the Shunamite woman who used to provide lodging for the prophet Elisha recognized that he was a holy man because flies never bothered him or his food. The presence of flies then symbolizes an excessive concern with the physical. The people who ignored Moses' instructions in Exodus 16,19 not to try and leave over part of the manna which fell on the first day learned their lesson because their left-overs became worm-eaten and stank. We read in Malachi 2,3: "I will strew dung upon your faces, the dung of your festival sacrifices, and you shall be carried out to its heap." The presence of flies and their ilk round the sacrificial meat is a clear sign of a curse. We have stated that our own table should serve as our private altar, i.e. as the visible symbol that we should strive for holiness.