In Ancient Egypt, it appears that after an initiate had passed through the lesser mysteries, as part of the greater mysteries, there was what was described in the Hermetica as their highest initiation, called the Black Rite.
This is described in the Hermetica by Isis as having been passed down to her by a being called Kemaphis, who is said to have received it from Hermes himself.
This rite is said to “give perfection”.
I would suggest that the name Kemaphis, which is the source of the Black Rite, is connected with Kematef, which is the Ancient Egyptian representation of the primordial life-force that resided in the chaos of darkness prior to creation. In Ancient Thebes this was the earliest form of Amun. In Heliopolis his equivalent was Atum.
This being would also have its representation as the earliest form of Osiris, who represents the dark monadic seed of every being, and thus relates to the saying, “Osiris is a Dark God”, and “He who is Lord in the perfecting black.”
This level of initiation (the Black Rite) related to the inner marriage which consummates in the second birth and contact with the monad – the dark light.
From the Hermetica:
“He who is Lord in the perfecting black,” might thus mean that Osiris, the masculine potency of the soul, purified and perfected the man on the mysterious dark side of things, and completed the work which Isis, the feminine potency of the soul, had begun on him.
That, in the highest mystery-circles, this was some stage of union of the man with the higher part of himself, may be deduced from the interesting citations made by Reitzenstein (pp. 142-144) from the later Alchemical Hermes-literature; it clearly refers to the mystic “sacred marriage,” the intimate union of the soul with the logos, or divine ray…. The Lesser Mysteries, he tells us, commenting on the text of the Pagan commentator, pertained to “fleshly generation,” whereas the Greater dealt with the new birth, or second birth, with regeneration, and not with genesis.
What this black was to the Egyptians related to why they called Egypt the Black Land. This they also linked with the black pupil of the eye and also the core of the heart.
Again from the Hermetica:
Egypt, the “sacred land” par excellence, was called Chemia or Chem (Ḥem), Black-land, because of the nature of its dark loamy soil; it was, moreover, in symbolic phraseology the black of the eye, that is, the pupil of the earth-eye, the stars and planets being regarded as the eyes of the gods. Egypt, then, was the eye and heart of the Earth; the Heavenly Nile poured its light-flood of wisdom through this dark of the eye, or made the land throb like a heart with the celestial life-currents.
Nor is the above quotation an unsupported statement of Plutarch’s, for in an ancient text from Edfu, we read: “Egypt (lit. the Black), which is so called after the eye of Osiris, for it is his pupil.”
Ammon-Kneph [Kematef, described above as the primordial life-force residing in darkness prior to creation], too, as we have seen, is black, or blue-black, signifying his hidden and mysterious character; and in the above-quoted passage he is called “he who holds himself hidden in his eye,” or “he who veils himself in his pupil.”
This pupil, then, concludes Reitzenstein (p. 145), is the “mysterious black.”
All of this is esoteric symbolism points to the Black Rite being an initiation into the dark light of Spirit – the monad. This was symbolised as the dark pupil of the eye, which eye belonged to Osiris. Another form of the dark light was Kematef, the primordial form of Amun.
Of course Osiris means “Throne of the Eye”. Osiris represents the monadic spark at the core of the human being, which spark is the seat of the Eye of God (Ra). The “Black Land” of Egypt was also understood as made of the fertile darkness of Osiris – meaning the monadic life-force itself.
We can therefore see that for the Ancient Egyptians, the essence of their understanding of Egypt was that it was the physical embodiment of spirit – the infinitely fertile dark light from which all creation emerged.
The pyramid, which was an initiation temple, represented the primordial mound, at the centre of which was the seed or egg created by Kematef as the fertile foundation of all creation that would later come through Ra, the creator. Passing through the initiatory rites within the pyramid would, in the greater mysteries, likely lead to this central core where the initiate would, in the Black Rite, connect soul to spirit and awaken to the divine ray / monadic dark light that they were and are prior to all creation, and there access the power prior to all creation. This is how the black rite initiation, which was the linking up of soul to monad, occurred within the complexes of the pyramid initiation temples.