Exodus 20:19
17 “You shall not covet your neighbor’s house. You shall not covet your neighbor’s wife, nor his male servant, nor his female servant, nor his ox, nor his donkey, nor anything that belongs to your neighbor.” 18 All the people were seeing the thundering and the lightning, and heard the sound of the horn, and saw the mountain smoking—and when the people saw it they trembled with fear and kept their distance. 19 They said to Moses, “You speak to us and we will listen, but do not let God speak with us, lest we die.” 20 Moses said to the people, “Do not fear, for God has come to test you, that the fear of him may be before you so that you do not sin.” 21 The people kept their distance, but Moses drew near the thick darkness where God was.
Isaiah 30:27
25 On every high mountain and every high hill there will be streams flowing with water, at the time of great slaughter when the fortified towers collapse. 26 The light of the full moon will be like the sun’s glare, and the sun’s glare will be seven times brighter, like the light of seven days, when the Lord binds up his people’s fractured bones and heals their severe wound. 27 Look, the name of the Lord comes from a distant place in raging anger and awesome splendor. He speaks angrily, and his word is like destructive fire. 28 His battle cry overwhelms like a flooding river that reaches one’s neck. He shakes the nations in a sieve that isolates the chaff; he puts a bit into the mouth of the nations and leads them to destruction. 29 You will sing as you do in the evening when you are celebrating a festival. You will be happy like one who plays a flute as he goes to the mountain of the Lord, the Rock who shelters Israel.
Notes and References
"... Sinai is not the only background that portrays the image of speech in the midst of fire. The actual phrase “tongues as of fire” occurs in two Old Testament passages. Isaiah 30:27—30 refers to God’s “descending” (verse 30) from his temple (“a remote place” [verse 27], “the mountain of the Lord” [verse 29]) and appearing in “dense ... smoke ... His tongue is like a consuming fire [verse 27]... The Lord [comes] ... in the flame of a consuming fire” and “will cause His voice of authority to be heard [verse 30].” This itself alludes to the prototypical Sinai theophany ..."
Beale, G. K. Handbook on the New Testament Use of the Old Testament: Exegesis and Interpretation (p. 126) Baker Academic, 2012