Deuteronomy 4:11

Yahweh said to Moses, “Behold, I will come to you in a thick cloud, so that the people may hear when I speak with you and may also believe in you forever.” Then Moses told the words of the people to Yahweh.

Now Mount Sinai was all in smoke because Yahweh descended upon it in fire; and its smoke ascended like the smoke of a furnace, and the whole mountain trembled violently.

He made darkness His hiding place, His canopy around Him, Darkness of waters, thick clouds of the skies.

Clouds and thick darkness are all around Him; Righteousness and justice are the foundation of His throne.

For you have not come to a mountain that can be touched and to a blazing fire, and to darkness and gloom and whirlwind,