Trumah: guarding the sacred

The core of the Mishkan is the aron.  The a aron contains the tablet s. But the tablets are inaccessible.  They are Surrounded by numerous barriers:the caporeth with its Cherubim, the Parocheth, the inner sanctum etc.  It makes the core unknowable and mysterious.   Yet, the core is in the public domain. The innermost secret is known by everyone.

The Parsha ends with the word nechosheth, copper.  I think  this is an allusion to the serpent (nacash) of Eden , and is a key to understanding the idea of the sacred.   The  temptation to violate the holy barrier is the essence of the sacred.  That battle between curiosity  and the proprietary is the home of sanctity.

The public knowledge of the structure and contents of the Mishkan  only adds to the temptation.  The. Cherubim reinforces the analogy. They fly over the core of the Mishkan, the tablets. They adorn the  Procheth, just as they guard the path to Eden. The tablets are the forbidden fruit. They give wisdom, they reveal too much about the nature of Gd. They must be entombed and guarded lest their secret be revealed.  Yet, there is no secret at all.
Violating the sanctity of the Mishkan is like adultery. The revelation is that there is no revelation.