After gathering B'nai Yisrael together to inform them of the commandment to build the Mishkan and the kohanic garments, Moshe Rabbeinu first instructs them concerning the mitzva of Shabbos at the beginning of Parshas VaYakheil. Rashi, quoting the M'chilta, explains that this teaches us that the building of the Mishkan is not permitted on Shabbos. The Talmud in Tractate Shabbat (49a) further derives from the juxtaposition of these two mitzvot that the 39 categories of creative activity forbidden on Shabbos are derived from precisely those activities which were performed in the construction of the Mishkan.[1] Thus, Mishkan/Mikdash is directly linked by the Torah to Shabbos. Shabbos and Mikdash are linked even more directly by two identical passages in the Torah: "Es Shab'sosai tishmoru v'es mikdashi tira'u Ani Hashem" - "Keep my Sabbath, and fear my Sanctuary, I am G-d" (K'doshim 19:30 and B'Har 26:2). What is at the root of this connection?
R. Shimshon Pincus z"i, a noted lecturer in Eretz Israel, taught that the common denominator between these two concepts is the presence of the Shechina, the Divine Presence. Concerning Mikdash, this is readily apparent. The Torah introduces the concept of Mikdash by commanding and promising: "And you shall make for me a Sanctuary, and I shall dwell amongst you" (T'ruma 25:8). With regard to Shabbos, though, one needs to investigate into the rich body of halachos and midrashim to uncover this same theme. The halacha seems to treat Shabbos as a personality. It commands us to eagerly prepare for and anxiously await its arrival. The Tanai'm and Amora'im speak of Shabbos Malka (the Sabbath Queen) or Shabbos Kalla (the Sabbath Bride) (Bava Kamma 32b, Shabbos 119a). The group of kabbalists surrounding the Ari z"l in 16th-century Tz'fat gave this halachic theme additional body by arranging the joyful, melodious recital of selected chapters of T'hillim and poetic songs -- the Kabbalas Shabbos (greeting and acceptance of the Shabbos) section of tefila -- as we enter into Shabbos. Who is this personality that suffuses the entity of Shabbos? It is none other than the presence of the holy Shechina. Based on this concept, we can understand more fully the words of the Rambam (Hilchos Shabbos 30:2):
"What is the honor [of the Shabbos]? One is commanded to bathe... in honor of the Shabbos and wrap himself in tzitzis and sit with great seriousness longing for greeting the face of Shabbos as he would go to greet a king. The early Sages would gather their students on the eve of Shabbos and wrap themselves and say 'come, let us go out to greet the Shabbos King!'"[2]
This awareness of the presence of the Shechina on Shabbos helps explain many other halachos as well. The Talmud Yerushalmi (quoted by Tosfos, Shabbat 113b) states "b'torach hitiru sh'eilas shalom b'Shabbos" - "only with great difficulty, did the Sages permit greeting each other on Shabbos". Whereas it is understandable that business-related speech should be prohibited as it draws the mind away from the restful, spiritual spirit of the day (the prohibition of "v'dabeir davar"), the hava amina (original thought) of prohibiting ordinary speech requires explanation! If we view ourselves as in the presence of Hashem on Shabbos, minimizing even unnecessary conversation becomes readily understandable just as one would do in the presence of a king. A story is recorded of a Roman nobleman who described his experiences visiting the Second Temple. One of the noteworthy aspects that he observed was the utter silence in the Mikdash even though hundreds of Kohanim were involved in the 'Avodah (Temple service). In the presence of HaKadosh Baruch Hu, one does not engage in unnecessary speech!
R. Pincus further suggested that, on a deeper level, the prohibition of muktzeh or moving objects designated for work creates a heightened awareness of being in the presence of HaKadosh Baruch Hu. When in the presence of a king, one does not move a muscle without permission!
Even seemingly slight violations of the 'Avodah are punishable by a heavenly death sentence. Similarly, seemingly slight acts of creative work on Shabbos are punishable by death. In light of the fact that in both situations one is in the presence of Hashem, this becomes quite understandable.
Three times on Shabbos, we say in the tefillos: "v'hanchileinu Hashem Elokeinu b'Ahava Shabbos Kod'shecha" - "Hashem, our G-d, bequeath to us your holy Shabbos". At first glance, this phrase is difficult. Why do we ask Hashem to grant us something He has already given us? Perhaps the answer lies in the usage of the word nachala - inheritance. All other forms of acquisition (purchasing, acquiring from hefkeir (ownerless state), receiving a gift) are active and require a kinyan (act of acquisition). Inheritance is purely passive. But if one is unaware of the fact that someone left him assets in his will, he cannot claim possession of them. We ask Hashem to show us more and more of the beauty and depth of the Shabbos so that we can constantly claim more and more of it as our inheritance. May our in-depth study of this lofty mitzvah and experience we partake of once a week lead to our enhanced spiritual enjoyment of the mattana tova, the great gift originally stored in Hashem's "heavenly treasury" (Shabbos 10b), of the Shechina's weekly presence in our shuls and homes.
[1] See introduction to Eglei Tal where he shows that the two d'rashot are two aspects of the same idea - the definition of labor from the perspective of keeping Shabbat is that which was done in the Mishkan, and therefore it may not be done on Shabbos: not in the Mikdash and not elsewhere.
[2] See Shiurim l'Zeicher Abba Mari for Rav Y.D. Soloveitchik's similar, fascinating approach to these sources and his contrast between Shabbos and Yom Tov.