What does it mean to see a sound? The Targum Pseudo-Jonathan takes the strange Hebrew phrase and leans into the miracle. "And all the people saw the thunders, and were turned back, every one as he heard them coming forth from the midst of the lights, and the voice of the trumpet as it will raise the dead, and the mountain smoking; and all the people saw and drew back, and stood twelve miles off" (Exodus 20:15).
Three details explode off the page.
First, the people saw sound. The Targum preserves this synesthesia — the thunders had visible bodies, streaming out from the midst of the lights on Sinai. At the giving of the Torah, the senses overlapped; ears saw and eyes heard. This is what revelation feels like from the inside: an experience that breaks the usual compartments of perception.
Second, the trumpet's voice will raise the dead. The Targum inserts an eschatological reference the Hebrew never makes. The shofar at Sinai is the same shofar that will sound at the final redemption, when the tombs open and the dead rise. Revelation and resurrection are two blasts of the same horn.
Third, and most concrete — the people drew back, and stood twelve miles off. The Targum does not leave the distance vague. Twelve miles. This is not fear; it is physics. The Shekinah at full intensity pushes bodies away. Later rabbis would measure Sinai's aura by those twelve miles — the length of the entire Israelite camp, stretched out at the boundary of what human flesh can withstand.
The takeaway: the moment God spoke, Israel experienced what prophets, mystics, and the dying have reported ever since — the senses fused, the future broke through, and the distance between earth and heaven became impossible to measure.