We tend to think of "fruit" in two ways in natural language. One is as food that grows on trees and vines, sweet and delicious, and able to be eaten without harming the plant in any way. Another is as the things we produce, what our work yields for the betterment of the world. These are obviously connected: we are like trees, producing things that "feed" the world in some way, just as the tree produces fruit that feeds us. It makes sense, then, that the idea of fruit in the Bible is bound closely to the idea of goodness. Fruits that are eaten represent the desire for good and the energy to do what is good; fruit that is produced is the actual good that we go into the world and do.

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.