|The Sanctuary constituted a site for holiness, in addition to containing a space of even loftier holiness – the Holy of Holies.
This space of supreme holiness, the Holy of Holies, was the locus in this world where all barriers were dissolved, where contact was made with the world beyond, where the dimensions of this world were nullified to divine existence.
In the Holy of Holies, the divine being is not a light that a person gropes after in the dark, but a tangible existence directly before him.
It is the place where ordinarily no one can enter, because his individual existence would be immolated there.
Only the High Priest, after purifying and sanctifying himself as mandated by the Torah, entered that place once a year, and in so doing bound together place, holiness, and man.
Rabbi Adin Steinsaltz