When speaking of the 2nd set of 10 Commandments, the Torah in Deuteronomy says: “It was a great voice, without end.” The Talmud comments on “without end” and says, there was no echo.
Well, what were the circumstances? Would natural law have no echo? Then, what’s the big deal. Why even mention it? And if the natural law would have an echo in that circumstance, and a miracle occurred to void that echo, what’s the point? Why make a nature-changing miracle just for an audio effect? And why is this important to know?
The Lubavitcher Rebbe has a simple, yet beautiful insight. Why do some rooms have an echo and other rooms do not? Well, it depends on the material in the room. If there’s carpet and drapes and lots of fabric there won’t be an echo, because the voice/sound gets absorbed. But if the room has little or no fabric and non-porous hard walls, then there will be an echo because the voice can’t get absorbed and so it bounces back.
No Echo at Sinai, says the Rebbe, is a very important message for all generations. The goal and purpose of Torah is to penetrate all of existence, to be absorbed in our lives. If we hear the words of Torah and they bounce off, Torah has not fulfilled its purpose. We ought to let it in!