Pour out
'Pouring out the vials upon the earth, which contained the plagues,' in Revelation 16:1, signifies influx of the reformed into the church, or into people who study and receive the doctrine of justification by faith alone.
(Референце: Apocalypse Explained 16; Apocalypse Revealed 676)
Flies
The swarms of flies that were sent upon Egypt signify the falsities in the extremes of the natural man, which are called sensual. Swarms of flies, as in Exodus 8:21, signify the falsities of malevolence.
(Референце: Arcana Coelestia 7441)