One of the main effects of a mitzvah (commandment) is to connect a Jew with his G‑d. The word mitzvah comes from the root shared by such words as tzoveth (company) and betzafto (together) denoting unity. Mitzvoth thus serve as the primary device to unite oneself with the Creator. The mezuzah, as one of the 613 mitzvoth of Torah, and, more specifically, one of the 248 positive commandments, serves this purpose as well. Similar to tefillin, however, which, physically bound to one’s hand and forehead, exemplify this concept in a literal sense, so too the mezuzah bears special significance in connecting its owner to the Creator.

The Talmud relates the following story: The last Parthian King Ardavan IV (Artaban, Artevan) sent a pearl of purest radiance to Rabbi Yehudah HaNasi (Judah the Prince, known as Rebbi) and requested: Send me something equally precious in return. Rebbi sent him a mezuzah. Ardavan sent back word: I sent you something beyond price, and you sent me something that sells for a debased coin of no value! Rebbi replied: My desirable things and thy desirable things are not to be compared unto her. Besides, you sent me something that I have to guard; whereas I sent you something that guards you while you lie asleep, as it is said: When thou walkest, it shall lead thee, When thou liest down, it shall watch over thee. (Proverbs VI, 22)

One phrase in this very popular story, “My desirable things and thy desirable things are not to be compared unto her,” remains obscure, and calls for further inquiry. The sages explain it as follows:

King Solomon, the wisest of men, declared,

Accept my teaching rather than silver, Knowledge rather than choice gold. For wisdom is better than pearls, and all desirable things are not to be compared unto her. (Proverbs VIII, 10-11).

In another place he states,

Happy is the man who finds wisdom, the man who attains understanding. Her value in trade is better than silver, her yield, greater than gold. She is more precious than pearls; all of thy desirable things cannot be compared onto her. (Proverbs III, 13-15)

The sages explain that in the first quote, the expression “desirable things” connotes religious acts and good deeds; while in the second quote, “thy desirable things” refers to gems and precious stones. Rabbi Acha explained in the name of Rabbi Tanchuma ben Rabbi Chiyya:

My desirable things and thy desirable things are not to be compared unto her, for the Prophet said:

But let him that glorieth glory in this, that he understandeth, and knoweth Me. (Jeremiah IX, 23)

A mezuzah, according to Rebbi, is the symbol of the knowledge of G‑d, allowing its possessor to “glory in this, that he understandeth, and knoweth Me,” and thus was incomparable with any pearl or precious stone in the treasury of the king – “My desirable things and thy desirable things are not to be compared unto her.”

It remains to be understood, however, in what sense a mezuzah is a symbol of the knowledge of G‑d. Despite the great and profound ideas expressed in the text of the two chapters Shema and Vehayah inscribed on the mezuzah parchment, it is not to be read but rolled up, covered and affixed to a doorpost. How exactly does it convey to its beholder the knowledge of G‑d?

The true meaning of the word “knowledge” actually connotes unity. The concept of knowledge presupposes existence of two entities – the knower and the subject of his knowledge. The process of knowing is penetration by the Knower of the subject and his total absorption and unification with it. Only when the knower becomes one with the subject does he possess knowledge of the subject. We thus find in the Biblical account of Creation the expression:

And Adam knew Eve. (Genesis 4:1)

The same Hebrew word “Da’ath,” is used for the intimate union of the first man with his wife and for the concept of knowledge1. Thus, in the kabbalistic terminology of the Sefirotic system, when the Father – Chokhmah (Wisdom) is united with the Mother – Binah (Understanding), this union is called Da’ath (Knowledge). When Adam tasted from the forbidden Tree of Knowledge, which in Kabbalah represents the central column of the Sefirotic tree (in fact resembling the shape of a mezuzah scroll), the unity of G‑d and His Holy Name was damaged, introducing death into the world.

The mezuzah, inscribed with the declaration of the unity of G‑d, penetrates the corporeal space of human habitation and permeates it with holiness, allowing the dweller therein to unite with the Source. Thus the knowledge of G‑d embodied in the mezuzah is a device by which one can achieve intimate unity with the Creator.