Exodus 20:21

20:21 The people kept their distance, but Moses drew near the thick darkness where God was.

Leviticus 16:2

16:2 and the Lord said to Moses: “Tell Aaron your brother that he must not enter at any time into the holy place inside the veil-canopy in front of the atonement plate that is on the ark so that he may not die, for I will appear in the cloud over the atonement plate.

Deuteronomy 5:22

The Narrative of the Sinai Revelation and Israel’s Response

5:22 The Lord said these things to your entire assembly at the mountain from the middle of the fire, the cloud, and the darkness with a loud voice, and that was all he said. Then he inscribed the words on two stone tablets and gave them to me.

Isaiah 45:15

45:15 Yes, you are a God who keeps hidden,

O God of Israel, deliverer!

Hebrews 12:18

12:18 For you have not come to something that can be touched, to a burning fire and darkness and gloom and a whirlwind