Hebrews 12:18-21

For you have not come [as did the Israelites in the wilderness] to a [material] mountain that can be touched, [a mountain] that is ablaze with fire, and to gloom and darkness and a raging storm, And to the blast of a trumpet and a voice whose words make the listeners beg that nothing more be said to them. [Exod. 19:12-22; 20:18-21; Deut. 4:11, 12; 5:22-27.] For they could not bear the command that was given: If even a wild animal touches the mountain, it shall be stoned to death. [Exod. 19:12, 13.] In fact, so awful and terrifying was the [phenomenal] sight that Moses said, I am terrified (aghast and trembling with fear). [Deut. 9:19.]