Deuteronomy 4:11
And you came near and stood under the mountain. And the mountain burned with fire to the midst of heaven, with darkness, clouds, and thick darkness.
Deuteronomy 5:23
And it happened when you heard the voice out of the midst of the darkness, for the mountain burned with fire, you came near me, all the heads of your tribes and your elders,
Exodus 19:16-18
And it happened on the third day in the morning, that there were thunders and lightnings, and a thick cloud upon the mountain. And the voice of the trumpet was exceedingly loud, so that all the people in the camp trembled.
Exodus 20:18-19
And all the people saw the thunderings, and the lightnings, and the noise of the trumpet, and the mountain smoking. And when the people saw, they trembled, and stood afar off.
Hebrews 12:18-19
For you have not come to the mountain that might be touched and that burned with fire, nor to blackness and darkness and tempest,