Here is a link to a recent story describing the use of CT scans to examine ancient Egyptian mummies non-invasively, with remarkable images of a newly-scanned mummy from the 20th to 26th dynasty period (anywhere between about 1187 BC to 525 BC).

Note the crossed hands of the mummy, clearly visible in the video above, which is very representative of ancient Egyptian funerary practices and which John Anthony West discusses in some detail in his groundbreaking 1979 work, Serpent in the Sky: The High Wisdom of Ancient Egypt.

Because he argues that the ancient Egyptians were consciously manipulating harmonic forces which are beyond much of the knowledge of science today (see the previous posts here, here, and here), he believes that number and symbol were of paramount importance to everything the Egyptians did. He argues that the crossed arms of the mummy point to the number four, the Pythagorean number of physical substance, as well as to the number five, which transcends matter -- a very powerful concept and quite appropriate for funerary symbolism.

Note the crossed arms and the crossed crook and flail in the images on the funerary equipment of Tutankhamun in the photograph below:

Speaking of the number four and the symbol of the cross, John Anthony West writes in Serpent in the Sky:
Fire, air, earth, water. The ancients chose with care. To say the same thing in modern terms requires more words, and none stick in the memory. Active principle, receptive principle, mediating principle, material principle -- why bother with such abstractions when fire, earth, air and water say the same and say it better.

In Egypt, the intimate connection between Four and the material or substantial world was applied in symbolism. We find the four orientations, the four regions of the sky, the four pillars of the sky (material support for the realm of the spirit), the four sons of Horus, the four organs, the four canopic jars into which the four organs were placed after death, the four children of Geb, the earth.
[. . .]
This is the cross of matter, upon which all of us are pinned. Upon the cross, the Christ, the cosmic man, is crucified. By reconciling its polarities through his own consciousness, he attains unity.

It is this same principle of double inversion and reconciliation that lies behind all religious Egyptian art and architecture. The crossed arms of the mummified pharaoh -- who (whatever his personal traits may have been) represents successive stages of cosmic man -- holds the crossed scepter and flail of his authority. Schematically, the point where the two arms of the Christian cross intersect represents the act of reconciliation, the mystical point of creation, the 'seed.' Upon a similar scheme, the exalted, mummified pharaoh represents the same abstract point.

The cross and the mummified pharaoh thus symbolize both Four and Five. 50-51.
Mr. West follows up this remarkable insight with another which is pertinent to this discussion. First, however, note that the article linked above, with the story about the recently-scanned mummy at the Smithsonian, refers to a newly-expanded exhibit at the Smithsonian which will "explore ancient Egyptian life, religious beliefs and how burial practices serve as windows into ancient cultures, revealing how archaeologists and physical anthropologists gain these insights through their research." It can only be hoped that those insights are being informed by those already recorded by John Anthony West, but it is doubtful.

In any event, Mr. West later writes this observation, which should be clearly kept at the forefront of the consciousness when observing anything related to Egyptian burial practices, including the images of the mummy in the video above: "Now when death is regarded not (as with us) as an ultimate dissolution, but rather as a transitional (and crucial) stage of a journey, then the apparent Egyptian preoccupation with death becomes exactly the opposite of what it seems to be. It is, in fact, a preoccupation with life in the deepest possible sense" (95).

These are important matters which bear further examination and contemplation.