A symbol of the sexual seed, the sacred sperm, the Ens Seminis.
Psalm 69:36: "The seed of his servants shall inherit it: and they that love his name shall dwell therein."
"Ancient populaces worshiped the corn, wheat and rice, because they represent the sacred seed. Mayas and Nahuas symbolized the Mercury of the Wise with corn. The Middle East and Europe saw the blessed seed in the wheat. China, Japan and India saw the sacred sperm in the rice. We transform the Ens Seminis into creative energy, which means into Mercury, only by the science of transmutation. Whosoever possesses the Mercury of the Wise can create within himself the superior existential bodies of the Being. Whosoever possesses the Mercury of the Wise within himself will abide in the city of Heliopolis. God will save Zion by virtue of the Mercury of the Wise. The interior cities will be constructed, and the Initiates will dwell in them and inherit them. A City of Light, a Heavenly Jerusalem, must be constructed within each human being." - The Pistis Sophia Unveiled