What reallyhappened up on Mount Sinai is, for Jews, the whole kazoo. Everything depends on it. Like similarly preposterous claims at the center of every religion, not only is Sinai logically impossible, but how you reconcile its paradox determines everything yet to follow.
Sinai is impossible for the simple and logical reason that the infinite cannot meet the finite without one of them getting destroyed. You may claim that God literally spoke and wrote the words on the tablets—in which case God effectively becomes finite. Or, you can resort to the poetry of MidrashTanchuma (s.v. B’reishit), for example, and say God wrote the Torah in “black fire on white fire,” in which case, in order to read Torah, the reader must become infinite. But there’s more.
If God somehow could speak all those words and, therefore, what we have in the Torah is an infallible record of the divine will, then liberal Judaism not only is no longer viable, but is also a terrible mistake. If, on the other hand, the words are essentially human (for example, Moses was “inspired”), then the Torah has no more claim on our behavior than any other equally “inspired” literature and orthodoxy, and in turn, collapses. Neither option is acceptable. The trick is to find some way to maintain that somethingreallyhappenedon Sinai but it is not literally what the Torah says. (Welcome to liberal Judaism.)
Fortunately we are not the first generation that has tried to solve this conundrum. The Chasidic master Naftali Tzvi Horowitz of Ropczyce ( 1760?1827) , in his Zera Kodesh (2:40a, Jerusalem, 1971) offers a dazzlingly relevant solution. (Note : The complete translation of this teaching appears in my book, The Way into Jewish Mystical Tradition [ Woodstock, VT: Jewish Lights Publishing, 2000].) The Ropczycer begins his teaching by citing Sh’mot Rabbah (29:2), where “I am Adonai your God” (Exodus 20:2) is set against “ Adonai spoke with you face to face” (Deuteronomy 5:4). Rabbi Levi went on to suggest that what happened on Sinai was (in essence) cardiac surgery: the Shem Ham’forash —the Tetragrammaton, the Ineffable Name of God, the four-letter Name yod, hei,vav,hei—was inscribed on our hearts.
Rabbi Naftali Tzvi Horowitz then continues with a teaching he heard from his own master, Rabbi Mendl Torum of Rymanov (d. 1815). He taught that at Sinai we did not hear the whole Torah or even the ten utterances! All we heard there from God was the first letter of the first word of the first utterance: alef , “ I [ anochi— first letter alef ] am Adonai your God . . .” (Exodus 20:2). But alef , as the master historian of Kabbalah, Gershom Scholem, points out, is technically not silent ( On the Kabbalah and Its Symbolism [New York: Schocken Books, 1965], p. 30). Instead, it is the noise of the larynx clicking into gear and therefore the mother of all articulate speech. It may also just be the softest audible noise in the universe. In other words, while it may not have been very loud, there was indeed somethingto hear.
The Ropczycer continues: We can now also resolve the apparent contradiction between Deuteronomy 4:15, “You saw no image when Adonai your God spoke to you at Horeb [Sinai] from out of the fire” (i.e., there was nothing to see!), and Deuteronomy 5:4, “ Adonai spoke with you face to face at the mountain from out of the fire” (i.e., something was visible). At Sinai, in other words, we couldn’t see God, but we did seeGod’s voice!
We also have a numerical connection, suggests the Ropczycer, between the yod,hei,vav,hei Name of God and the letter alef . The letter alef is constructed of two letter yod s (the tenth letter of the alphabet) on either side of the letter vav (the sixth letter) joining them in the middle. These two 10s and one 6 make a total of 26, just as the four-letter Name of God, yod (10), hei (5), vav (6), and hei (5), also totals 26! In kabbalistic studies this is indeed a very, very important number.
(Sephardic Jews, by the way, know nothing of our Ashkenazic preoccupation with the number 18—drawn from the word for “life,” chai , 18, chet  and yod . Instead, they chose the far more spiritually mysterious 26. Just imagine how much more money they must give to t’zedakah!)
This number 26, in turn, says Naftali Tzvi Horowitz, also evokes a human face. Our two eyes resemble two letter yod s, and the nose between them looks like a letter vav . In other words, on every human face there is a letter alef, which in turn evokes 26, and we all know what that signifies.
This further explains the odd passage in Genesis 1:27 that states that we are created in the image of God. Thus, while God can have no image, God can and does have a Name, and the facial alef engraved on everyone’s punim (two eyes and a nose) has the same numerical equivalent, 26, as God’s Name, yod, hei, vav and hei ! Indeed, as we are instructed by the Psalmist, “I set the [Name of] Adonaibefore me continually” (Psalm 16:8) may mean simply to look at one another!
And, therefore, when our Sages spoke of this keeping God ever before you as a great principle of the Torah, they meant that when we stood at Sinai and heard only the barely audible sound of alef , the shape of the letter alefwas simultaneously also revealed to us as being smack dab in the middle of each other’s faces. And just that is the great revelation.
This also explains, while we’re at it, the cryptic expression in Exodus 20:15 that literally reads: “And all the people saw the thunder.” In other words, they saw what was normally only heard. We all saw the letter alefevoking the Name of God. And at that moment we also all saw and understood that this letter was also engraved in the physiology of our own faces!
In other words, the voice of God that we heard was actually the Name of God we saw—on one another’s faces. And just that alef, the first letter, is a Torah seed of Sinai.
Rabbi Lawrence Kushner is the Emanu-El Scholar at Congregation Emanu-El of San Francisco. He is the author of several books on Jewish spirituality including a new novel, Kabbalah: A Love Story ( New York: Morgan Road Books, 2006).