One of the most amazing things about it is the perception of the colors in the lower bodies, which are like the air. Perception relates to their colors just as it relates to the colors in dense bodies. On the gates of their cities are necklaces of ruby stones, each stone of which is more than five hundred cubits. The height of the door in the air is great, and upon it hangs a number of weapons. If the kingdom of the entire earth were to come together, what would be fulfilled in it, and they have darkness and light without a sun alternating between them, and by their succession they know time, and their darkness does not obscure sight from its perceiver, just as light does not obscure it, and some of them invade.