Finally an answer to your question
re the double cube of the king's chamber.
Stechinni delivers a lot of dry mathematical
observations about the king's chamber and the coffer,
but he never comes right out with any
interpretation that connects with Egyptian
religious or cultural history.
The most significant cultural connection theory I've found
comes from Robert Lawlor. You can look at a diagram in
the attachment to examine the geometry.
Lawlor links the double square to the Throne of Osirus,
also called the Throne of the World, that appears
in Egyptian iconography as the Pharoah's seat in his role as
god/king. In other Egyptian imagery Osirus himself sits on this
throne in the underworld.
Lawlor's explanation of the throne's geometry fits it in
with the symbolism of foundation stones and foundation squares
that appear in other south asian cultures. The Iku of the Sumerians,
for example,and similar Hindu altars and temple floor mandalas
are all squares representing the point of origin or the point where
heaven touches earth. From here divine influence expands outward.
In the attachment, the diagonal line crossing a double square becomes
the radius of a circle that establishes the corners of a larger square that
adds a gnomon to the original equal in area to the small square appearing
in the lower right corner of the throne.
As Lawlor sees it, this is the first step in a gnomonic expansion
from the foundation square into the world itself.
Lawlor does not establish any link to the design of king's chamber,
but after following his logic on the role of the double square in shaping
the Throne of the World, I think it is worth considering the potential
significance of placing of a double cube at the center of a structure that
is a symbolic miniature of the earth itself.
A quick word about gnomons. A gnomon is a unit that can be
added to any figure that makes it larger or smaller with
out changing its shape. More on this later.
The coffer functions as a gnomon too. Stechinni points out
that the exterior volume of the coffer is double the interior volume.
Stechinni spends a lot of time building up a case that the two volumes
are measured in a unit called an artaba. This was once a widely used unit
for the measurement of grain. The coffer's interior volume measures 40
cubic artabas, its exterior volume is 80 artabas.
For what its worth, this is a square-root-of-2 relationship and the
royal cubit that measures the chamber and the edge of a cubic artaba
used in the coffer are also in a square-root-of-2 relationship.
There may be another reason for using a grain measure in the coffer.
One often reads speculation that the coffer was intended as the tomb
of Pharoah Cheops who built the Great Pyramid.
Instead I think it seems possible that the coffer is intended as the
symbolic resting place of the eternally dead and reborn Osirus.
The significance of the grain-measuring artaba may lie in the association
of the Osirus with wheat in the cycle of planting and harvest.
The image of sprouting wheat in association with Osirus can be seen
in the link provided here.
One final word on gnomonic expansion as a symbol of the divine
creative force the Greeks called Logos . The Egyptians weren't the only ones
to use it.
The Pythagorean symbol of the divine called the Tetractys
seen right * * *
if the formatting * * * *
is an expression of gnomonic expansion. Likewise Jewish Caballists
borrowed this arrangement and put the letters a of the Name of God in
Hebrew on these dots in what amounts to an endorsement of the
Whether Lawlor is right in his theory of the Throne using gnomonic
expansion to express divine authority. I don't know. But if he is, maybe
something like this is also behind the plan of the king's chamber.
-------------or maybe this is all just an exercise in pretzel logic.