The Three Barriers
Foundations of Internal Alchemy: The Taoist Practice of Neidan, by Wang Mu, pages 34-35
In the ascending path along the Control vessel, three points are arduous to overcome. The alchemical texts call them “barriers” (or “passes,” guan). Xiao Tingzhi (fl. 1260–64), a fifth-generation disciple of Zhang Boduan, wrote in his Jindan wenda (Questions and Answers on the Golden Elixir):
"Someone asks what are the three Barriers on the back. The one behind the brain is called Barrier of the Jade Pillow (yuzhen). The one in the Spinal Handle (jiaji) is called Barrier of the Pulley (lulu). The one at the junction of Water and Fire is called Barrier of the Caudal Funnel (weilü)."
The Barrier of the Caudal Funnel is located in the lowest section of the spine. The Barrier of the Spinal Handle is in the back, across from the heart. The Barrier of the Jade Pillow is behind the head, below the identically-named acupuncture point, across from the mouth.
This is one of several articles on Internal Alchemy available from the Golden Elixir website. See the complete index.