The title of ninth Sephira, or emanation of the Tree Of Life, is YSVD (Yezod). It is the Sephira of the Lunar magick of Aub, or Ob, the Serpent (whence “obeah”).
The Serpent is a Symbol common to the Yezidi, Voodooists, Tantrics, and Thelemites.
Yezod or Yesod as the secret center of the Yezidi is an apt description of the Sephira wich corresponds to the sexual center in the human body. Yesod means “Foundation”, and the Hadit of the Thelemites, is the Foundation of the World, as Yesod is the foundation of the Tree Of Life.
The accursed God of the South is, then no other than the lord of the reproductive forces typified by the southernmost Sephira-Yesod.
Yesod is attributed to the Moon. not to the Sun. The curious symbolism is explained by the connection of the Serpent or Dragon with the lunar current typified by Babalon- “for he is ever a sun, and she a moon”. The symbolism may be fathomed at the Hindu level of mythology where Shiva (the Indian Seth) is called “the god with the crescent” (i.e the moon) in the Bhagavad Gita. Also, Thoth the Moon-god, was originally the God of Sirius, identical with the Star-God-Seth, before the luni-solar mode of reckoning time supplanted the stellar reckoning.
This is the reason why the inverted pentagram, or pointed towards the south is usually abhorred as a seal of the devil. Is the seal of Satan because it invokes the snake sex, snake Obeah. The osirisian, and Christians, fled from this aspect of existence, and the pentagram of Set, the south, was considered the symbol of impurity and of abomination. It is still the star of Satan for those who consider the use the current of sexual magic as “evil” that is diabolic. Originally there was no moral pollution; it comes from the hands of the followers of the cult of the old Aeon, those represented in myth by God Dying: Adonis, Osiris, Christ, etc

Kenneth Grant
“The Magical revival”