The Sulfur is the sacred fire of Kundalini in the human being.
A symbol in alchemy of the sacred fire or Kundalini. Represented by 🜍.

The True Man
There are three mercuries:
The first Mercury is the Brute Azoth, the sacred sperm. The second Mercury is sexual energy, the outcome of the transmutation of the sperm. The third Mercury is the Mercury fertilized by Sulfur; in other words, it is the sexual energy already fecundated by the sacred fire; it is a mixture of energy and fire that rises along the dorsal spine in order to take us towards the inner realization of the Being.
What is that star, and who are these three magi? I tell you that the star is none other than the seal of Solomon, the six pointed star, symbol of the Solar Logos. Obviously, the upper triangle represents sulfur, that is to say, the fire. And what does the lower triangle represent in alchemy? It represents Mercury, the water. But, what kind of water do the alchemists refer to? It is the water—Mercury, they say—that refines the metallic radical number, in other words, the exiohehary, the sacred sperm. Undoubtedly, by means of the transmutation of our sexual secretions, that extraordinary water, that pure water, that Mercury of the secret philosophy, is elaborated. Samael Aun Weor
“The house of bread” in Aramaic and Hebrew [בית לחם]. “The house of meat” in Arabic [بيت لحم]. The Holy City of western religions and a deep symbol. The birthplace of King David and Jesus.