Targum Jonathan on Exodus
Touch it not with the hand; for he will be stoned with hailstone, or be pierced with arrows of fire; whether beast or man, he will not live. But when the voice of the trumpet is heard, they may go up (forwards) towards the mount.
Targum Jerusalem
No man shall touch it with the hand; for stoned he will be stoned, or fiery arrows will flee against him; whether beast or man, he will not live. When the trumpet soundeth, they may go up toward the mountain.