Apocalypse Revealed #423
423. And the sun and the air were darkened because of the smoke of the pit. This symbolically means that therefore the light of truth became thick darkness.
The sun and the air here symbolize the light of truth, for the sun symbolizes love, and the light from it, Divine truth. Consequently, when we are told that the sun was darkened, and with it the air, it symbolically means that Divine truth became thick darkness. That this resulted from falsities accompanying lusts is symbolically meant by its being because of the smoke of the pit.
Arcana Coelestia #197
197. With the most ancient people, who were celestial, a serpent meant being completely watchful, and so also meant their sensory perception by means of which they were to show vigilance to avoid being harmed by the evil. This is clear from the Lord's words to His disciples,
Behold, I send you out as sheep in the midst of wolves; so be shrewd as serpents and simple as doves. Matthew 10:16.
And also 'the bronze serpent' which was raised up in the wilderness and which meant the Lord's Sensory Perception. He alone is Celestial Man, and He alone is completely watchful and provides for everybody. Whoever beheld it therefore was delivered.