Exodus 20:18–21. "The End of the Law"
“Now when all the people saw the thunder and the flashes of lightning and the sound of the trumpet and the mountain smoking, the people were afraid and trembled, and they stood far offand said to Moses, “You speak to us, and we will listen; but do not let God speak to us, lest we die. ”Moses said to the people, “Do not fear, for God has come to test you, that the fear of him may be before you, that you may not sin. ”The people stood far off, while Moses drew near to the thick darkness where God was.”
(Exodus 20:18–21 ESV)