Chagigah 13 - How to teach mysteries
One should not teach the mystery secrets (of Kabbalah) other than to someone who understands them on his own, and even then he should only be told subject titles, but not the actual contents in detail. Some say it differently: anybody can be taught general ideas of Kabbalah, but to explain them in detail - that is only for those who can understand them on their own.
The reason for the two approaches is as follows: the first school says that it is impossible to transmit the mystery from a teacher to the student. Such attempt will inevitably result in misinterpretation and dangerous misunderstanding. The other, however, maintains, that it is possible to faithfully transmit deep secrets, provided that the student is worthy.
Here is one example of such teachings: " The Chayot (literally, live beings) angels ran to and fro, like the appearance of broken fire ." This can be understood that they were raising their heads above their level, but then immediately drawing them back, out of fear of Divine presence. This phrase also teaches a meditative device of swinging between to extremes in the understanding of Divine, like a pendulum, gradually expanding its swing.
What is meant by "broken fire?" It alludes to purifying gold, when the fire is darting through the openings in the shards. The word for "broken fire," "bazak," has the connotation of earthenware shards, and also of fire.
Art: Interior Scene, Called 'Mystery' By Edouard (Jean-Edouard) Vuillard