When hallucinatory auras present themselves to view, they look like clouds, thicker or thinner according to the nature of the hallucination. There is a kind of foggy crag under the left foot in the region of the pre-Flood people, and they spend their lives beneath it. Its fogginess is due to their hallucinations and keeps them at a distance from everyone else in the other world.
People who have lived lives of hatred and revenge give off auras of a type that causes fainting and induces vomiting. These auras are essentially poisonous. I am accustomed to examining them for their toxicity and thickness by means of a kind of dusky blue ribbon. As these ribbons evaporate, the aura also shrinks.
One of those who are called lukewarm came to me, acting as though he had repented. It did not feel like a trick, although I would have thought that he was hiding something inside. But the spirits were saying that they could not stand to have him near, that they were feeling the same sensation you feel when you are about to vomit, and that he was one of those who needed to be spat out.
Later, he started saying unspeakable things and was unable to stop, no matter how much pressure was put on him not to talk that way.
from Secrets of Heaven, Volume 2, Sections 1512, 1513