Deuteronomy 4:11
and ye draw near and stand under the mountain, and the mountain is burning with fire unto the heart of the heavens -- darkness, cloud, yea, thick darkness:
Deuteronomy 5:23
'And it cometh to pass as ye hear the voice out of the midst of the darkness, and of the mountain burning with fire, that ye come near unto me, all the heads of your tribes, and your elders,
Exodus 19:16-18
And it cometh to pass, on the third day, while it is morning, that there are voices, and lightnings, and a heavy cloud, on the mount, and the sound of a trumpet very strong; and all the people who are in the camp do tremble.
Exodus 20:18-19
And all the people are seeing the voices, and the flames, and the sound of the trumpet, and the mount smoking; and the people see, and move, and stand afar off,
Hebrews 12:18-19
For ye came not near to the mount touched and scorched with fire, and to blackness, and darkness, and tempest,