The giving of the Torah at Mt. Sinai on Shavuos made it possible for the spiritual to affect the physical, for G‑dliness to be introduced into the corporeal world. The mitzvos which Jews perform could now make the world a receptacle for the Divine.

Shavuos is the “Season of the giving of our Torah,”1 commemorating the time when, fifty days after the exodus from Egypt, the Jewish people stood at Mt. Sinai and received the Torah from G‑d.2 From then on Jews were a Torah nation, whose chief occupation would be Torah study and observance of mitzvos. They became “a kingdom of priests and a holy nation.”3

Even before this awesome event, our forefathers performed mitzvos, as the Talmud notes:4 “Our father Avraham observed the whole Torah before it was given, as stated, ‘Because Avraham listened to My voice and kept My charge, My commandments, My statutes and My Torah.’” But there is a cardinal difference between mitzvos performed before and after the Torah was given.

Joining of spiritual and physical

The Midrash states:5 “When the Holy One, blessed be He, created the world, He decreed and said: ‘The heavens belong to the L‑rd, but the earth He gave to the children of man.’ When He wished to give the Torah, He abolished the original decree and said: ‘The lower regions shall ascend to the upper regions and the upper regions shall descend to the lower regions.’”

Heaven represents spirituality and holiness, earth everything physical and mundane. The Divine decree that they be separate meant that spiritual actions could have no effect on physical objects. Our forefathers served G‑d with every fibre of their beings because they personally were of lofty spiritual stature, to the extent that they are called the “chariot” of G‑d.6 But precisely because their service came from their own strength, because they wanted to be spiritually whole and perform mitzvos, the effect of their mitzvos remained in the spiritual realm. The physical object used remained untouched by the mitzvah; it remained unsanctified, corporeal.7

At the giving of the Torah, G‑d removed the barrier between the physical and the spiritual. The heavens, that which is “upper,” would now be joined with the “lower,” with earth. The spiritual would affect the physical; the object with which a mitzvah was performed would now become sanctified; G‑dliness would permeate the corporeal world.

We are able to infuse G‑dliness into the physical world because our strength to do so, unlike our forefathers, comes from G‑d Himself, given at Mt. Sinai. Because G‑d desired that His presence should dwell specifically in this physical world, He gave us the ability that, through mitzvos, physical objects could become sanctified. Torah was not given to reveal G‑dliness in the spiritual realms. That could have been achieved through angels, or through souls as they are originally in the spiritual realms. The goal of the creation of a physical world, where souls inhabit physical bodies, is that the body should be cognizant of G‑d, that G‑dliness be revealed in the world, making it a fit dwelling place for the Divine. And this is achieved through living in the spirit of the Torah. The world and Torah are not separate entities. One is not a Torah-Jew only in an environment of Torah and outside follows the dictates of secular society. Even ordinary matters, eating, drinking, business affairs — they too must be done in a Torah way.8 G‑d dwells in the mundane as in the holy.

It follows from this that the giving of the Torah allowed not only that mitzvos would now permeate the physical, but that the mitzvos themselves would be on a higher level. Mitzvos before the Torah was given were limited to “heaven;” they were not commanded by G‑d and did not possess G‑dly vitality and therefore could not unite with the physical. Mitzvos performed after the Torah was given were infused with the power of G‑d’s command and, because G‑d transcends both “upper” and “lower,” He, and His mitzvos, can synthesize what are otherwise complete opposites.

Upper and lower in the Ten Commandments

At Mt. Sinai, it was the Ten Commandments which were openly given to the Jews.9 The Ten Commandments encompass the entire Torah, and the power of Torah to synthesize complete opposites is reflected in them.

The Ten Commandments seem to be comprised of two very different categories. The first few commandments, such as “I am the L‑rd your G‑d” and “You shall not have other gods,” are the loftiest expressions of G‑d’s unity. The rest consist of such simple commands as “You shall not murder” and “You shall not steal.” The latter category are things which are comprehensible even to the human intellect.

That G‑d combined both categories in the Ten Commandments expresses the synthesis of upper and lower, heaven and earth, which took place at the giving of the Torah. Both concepts — “the upper shall descend to the lower” and “the lower shall ascend to the upper” — are alluded to.

“The upper shall descend to the lower” means the upper commandments should be present also in the lower, such as the prohibitions against theft and murder. That is, the basis of the fulfillment of the latter must be because “I am the L‑rd your G‑d.” These commandments should be observed not only because human logic dictates so (for the purpose of an orderly, moral society), but principally because G‑d commanded them.10

If the latter category were to be separate from the former, leaving such mitzvos as the prohibitions against theft and murder to the dictates of the human mind, they could easily be ignored or distorted. Self-interest is a powerful force, and if personal desires dictate that one’s actions be contrary to morality or decency, not always will decency win out.11 Indeed, these laws may even be perverted. History has seen times, even recently, when murder was legitimatized for the “good” of society.

Even if the human intellect would invariably dictate the observance of such commands, it is the task of a Jew to unite all his actions with G‑d. Thus, “I am the L‑rd your G‑d” must be felt in everything a Jew does. Even those things comprehensible to the human mind must be permeated with G‑dliness, for to the Jew, everything is G‑dliness, everything can and should be sanctified.

The idea of “the lower shall ascend to the upper” also is alluded to in the Ten Commandments. There are, unfortunately, people who will murder or steal, on whom logical arguments are unavailing. It is only when G‑d Himself, in all His glory and majesty, commands “You shall not murder”, “you shall not steal,” that such people desist. For them, the latter category, the “lower,” is necessary in its most basic meaning. But “the lower shall ascend to the upper” teaches that even these people must think of G‑d and meditate on the profoundest meanings of “I am the L‑rd your G‑d.” All Jews through Torah can become one with G‑d, transcending all the worlds.

“I am the L‑rd your G‑d”

That “upper” and “lower” can be synthesized because G‑d provides the strength to Jews to do so, is alluded to in the first words of the Ten Commandments: “I am the L‑rd your G‑d.” These three terms represent three general levels in the revelation of G‑dliness.

“G‑d” represents the G‑dliness in creation. Everything contains a G‑dly spark, the revelation of which is commensurate to that object’s spiritual state. The more spiritual a thing, the greater the G‑dliness. It is for this reason that the word for “G‑d” in Hebrew — Elokim, has the same numerical value as tevah, which means nature.12 For this level of G‑dliness is invested in creation which G‑d has set within “natural” limits.

“L‑rd” represents the revelation of G‑dliness which transcends creation and it is that level where the past, present and future — which normally cannot coexist — are all one.13 The L‑rd is infinite, above time and place.

“I” refers to G‑d’s Essence, which is so lofty it cannot even be given a name, as stated: “I am who I am.”14 Not only is this loftier than the level of G‑dliness as invested in creation (“G‑d”), but is also higher than the revelation of G‑dliness which transcends nature (“L‑rd”). The level of “I” is not limited to anything — not to nature and not to the level transcending nature. The level of G‑dliness of “I” can therefore synthesize both those levels together, nature together with transcending nature, finity together with infinity. The Essence of G‑d is no more constrained to infinity than to finity.15

This is the meaning of “I am the L‑rd your G‑d.” At the giving of the Torah, every Jew is given the strength of “I,” which is not limited by or to anything. Jews are therefore able to combine the level of “L‑rd” — transcending creation, with “your G‑d” — the level of G‑dliness which can be grasped even by the human intellect. Jews must unite the commands “You shall not murder” and “You shall not steal” (“lower”) with the commands “I am the L‑rd your G‑d” and “You shall not have other gods” — the highest levels of G‑d’s unity (“upper”). There can be no distinction. The Torah was given to synthesize the upper and the lower, to introduce G‑dliness specifically into the physical, to make the world a receptacle for the Divine.

Likkutei Sichos, Vol. III, pp. 887-892