Exodus 20:18-21

All the people perceived the thunder and the lightning flashes and the sound of the trumpet and the mountain smoking; and when the people saw it, they trembled and stood at a distance. Then they said to Moses, “Speak to us yourself and we will listen; but let not God speak to us, or we will die.” Moses said to the people, “Do not be afraid; for God has come in order to test you, and in order that the fear of Him may remain with you, so that you may not sin.” So the people stood at a distance, while Moses approached the thick cloud where God was.