With regard to G‑d’s giving the Torah to the Jewish people at Sinai, Scripture informs us: “All the people saw the sounds, the flames....”1 Rabbi Akiva interprets this verse to mean that the Jews then “saw that which is heard, and heard that which is seen.”2 Thus, “the sounds” which by nature are normally heard were literally seen, and “the flames” which are customarily seen were actually heard.

It is axiomatic that “G‑d does not perform a miracle without a purpose.”3 We must perforce say that the above-mentioned miracle was central to the theme of G‑d’s giving the Torah. In what possible way were these phenomena related to the revelation at Sinai?

There exist fundamental differences between sight and sound, both with regard to the viewer and hearer, as well as with regard to the object seen or heard.

With regard to the person: Sight has a more profound impact on the viewer than hearing has on the listener. Accordingly, the person who sees something is surer of the information conveyed to him by his sense of sight than the listener is of that which is conveyed to him by his power of hearing.

This fact results in the law that “a witness [to an event] may not serve as a judge,”4 for, as the Gemara5 explains, since he actually saw the person commit the misdeed, it will be impossible for him to find extenuating circumstances and deal leniently with the perpetrator.

However, when a judge merely hears the testimony of witnesses, he is still capable of dealing leniently with the defendant by reason of extenuating circumstances. This is so, even when he is thoroughly convinced that the eyewitnesses are telling the complete truth, and that the person did indeed commit the misdeed for which he stands accused.

The difference between sight and sound with regard to the object seen or heard is as follows: Sight discerns the actual physical matter, while hearing detects something more metaphysical in nature: sound waves are spiritual, so to speak, in comparison to the gross, material objects revealed to the naked eye.

These two differences between sight and sound, with regard to the person and with regard to the object, are interdependent.6 As a physical being, man is naturally closer to the material than to the spiritual. It follows that he will grasp a material object — with his power of sight — more intimately and thoroughly than something spiritual, which he will only grasp from “afar” with his power of hearing.

This, then, is what is meant by “seeing that which is heard, and hearing that which is seen.”7 Spirituality is generally only “heard” by means of experiencing it from a distance. When G‑d gave the Torah to the Jewish people, however, He raised them to a level where they became capable of “seeing” and grasping spirituality through direct perception.

Conversely, the physical world, which had always been clearly seen by them, now became distant from them. Their heightened spiritual state made it difficult for them to “see” and fully grasp the corporeal; they were now only able to discern it with their weaker sense of “hearing.”

We thus understand that this miraculous occurrence was an integral element of receiving the Torah. Since at that time the Jews were granted a revelation of G‑d’s Essence, they were able to grasp spirituality with the more intense power of “vision,” while losing sight of their own corporeal being, which they were only aware of through the less direct sense of “hearing.”

Based on Likkutei Sichos, Vol. VI, pp. 119-122.