In most cases, "mouth" in the Bible represents thought and logic, especially the kind of active, concrete thought that is connected with speech. The reason for this is pretty obvious, but it also holds when people, for instance, remove a stone from the mouth of a well, which represents gaining access to spiritual ideas. The mouth is used for eating as well as speaking, of course. In those circumstances, it represents our first, most external perception of a new spiritual idea or desire. This also makes sense, mirroring the way tasting food in the mouth gives us an instant impression of the quality of the food.

Egyptians represent people who are in natural knowledge. In contrast, the Hebrews, people who are of the church, represent people in spiritual knowledge. The Egyptians also held the Hebrews to be so vile, as servants, that it was an abomination to them to eat with the Hebrews (Genesis 43:32), and also the sacrifices offered by the Hebrews were an abomination to them. (Exodus 8:26)

(Odkazy: Arcana Coelestia 5013)