Cow dung
In Ezekiel 4:15, this signifies that the prophet was to represent the corruption of the literal sense of the Word. (The Inner Meaning of the Prophets and Psalms 127)
Cities
Cities of the mountain and cities of the plain (Jeremiah 33:13) signify doctrines of charity and faith.
(Odkazy: Arcana Coelestia 2418)