The Egyptians contemplated the Holy Spirit (the Third Logos, Sephirah Binah, Shiva) in the form of a very sacred swan known as Kala Hansa.  This is a clear indication of the nature of the energy that must be rising on the energy vessels within the spinal medula of the Initiated Ones, in order to become completely enlightened: this energy is a manifestation of the Holy Spirit itself which, within the cube, reminds us of the Ninth Sphere (see the Physical Plane).