Kosa sheath
[Sanskrit kosha, “sheath”] A term used to describe that portion of the auric envelope immediately surrounding and interpenetrating the physical form.
Just as a comb builds up static electricity when used vigorously, just as walking on a rug builds up a similar charge, as does the rubbing of a glass rod with a piece of silk, so mankind as they daily come in contact with the vibrations of the world do build up a negative charge of electricity which manifests in this auric envelope and can cause undesirable conditions in the world of the individual. This static charge impedes action and the healthy flow of the light throughout the four lower bodies.
The daily transmutation of this effluvia can make the difference in one’s victory. For every tie with the mass consciousness that is broken means that much more freedom on the homeward path.
See also
Sources
Keepers of the Flame Lesson 24.