A Thought Appropriate For Shavuos
[At the giving of the Torah] All the people saw the sounds and the lightning, the blast of the ram's horn and the mountain smoking. The people trembled when they saw it, keeping their distance. (Shemos 20:15)
All the people saw the sounds - This is strange indeed. Sounds are heard, not seen. A parable will help to clarify this verse:
There was a musician who one day played his violin so sweetly and with such passionate joy that all bystanders, unable to restrain their emotions, exploded into frenzied and boisterous dance. Just then a deaf man passed by. Since he could not hear the music, the tumultuous dancers appeared to him like people who had gone raving mad. Had he understood that it was the thrilling music that inspired the dancing, he too would have joined in.
When G-d revealed Himself on Mount Sinai, and the people of Israel saw the Divine Light and the angels dancing, they understood that this dance was stimulated by the sweetness and beauty of the sound of Torah. Although they could not yet grasp the full significance of the Torah, they inferred from the joyous dancing of the angels that the Torah contained a rich treasure. They "saw the sounds" of the Torah without hearing - that is, understanding - its meaning, and pushed forward in an attempt to partake of the sweetness of its light.
(Degel Machaneh Ephraim)