In Genesis 21:7, this signifies to implant truth from good, or something spiritual from a celestial origin. (Arcana Coelestia 2643)

In Psalm 8:2, this signifies that praise can come to the Lord only through innocence, for this alone effects all communication and all influx. (Arcana Coelestia 5236[4]) 'The nurse,' in Genesis 24:59, signifies a state of innocence. 'The nurse,' in Genesis 35, signifies hereditary evil. 'A nurse,' as she feeds and nurses an infant, properly signifies the introduction of innocence by the celestial spiritual. But when 'Deborah, the nurse of Rebecca died and was buried,' it signifies that hereditary evil which the Lord received from His mother, which was nourished from infancy just like with other people, was later totally expelled forever.

(Odkazy: Arcana Coelestia 3183)

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.