The Targum Pseudo-Jonathan renders the theophany with thick sensory detail: "All the mount of Sinai was in flame; for the heavens had overspread it, and He was revealed over it in flaming fire, and the smoke went up as the smoke of a furnace, and all the mountain quaked greatly" (Exodus 19:18).
The Aramaic phrase "the heavens had overspread it" adds a detail absent from the Hebrew. The sky itself descended onto the mountain, so that heaven and earth met on that peak. The barrier between the two realms had been temporarily removed.
The fire is not ordinary fire. "He was revealed over it in flaming fire" — the flame is the revelation. What Moses and Israel saw was not God inside the fire; the fire was the shape God took for the encounter. The Aramaic is careful here, preserving God's transcendence even while narrating His appearance.
The comparison to "the smoke of a furnace" grounds the vision in something earthly. Everyone in the ancient Near East knew what a furnace looked like when it was running at full heat. Sinai looked like that, but magnified to cover an entire mountain. And the ground shook.
The rabbis understood this convergence — fire from above, smoke to the sky, the mountain trembling — as the moment creation paused. The Talmud in Zevachim 116a says all the nations heard the sound. Sinai was not a private Israelite event; it was a public cosmic one.
The takeaway: real revelation shakes the ground. If nothing moves, nothing was said.