זוהר שמות — דף רנא ע”ב

In the spirit Zkhout El are inscribed the letters Yod-Heh-Vav, which attach to it from above at the moment of union between the masculine and feminine. From there, holiness spreads in all directions to illuminate the world. This palace is connected to the palace that receives the supreme light and distributes it to the other palaces. From there extends the light that guides the righteous according to their deeds, and the mystery of the supreme union between the sefirot.