What's going on here? מַה זֶה?

During God’s revelation at הַר סִינַי (Har Sinai, Mount Sinai), the Torah says that “the people saw the thunder and the lightning” (Shemot 20:15). Thunder isn’t something that we normally can “see.” What does this pasuk mean?
  • Sforno says it means they concentrated on the thunder.
  • Rashbam says that they saw hail and stones falling.
  • Rashi says it was a miracle, and they actually saw the sound of thunder, even though this is normally impossible.
  • On a basic level, it is possible that here the word “see” really means “perceive.” In this case, the pasuk means that the people saw the lightning and heard the thunder.