He let you hear His voice from heaven to discipline you, and on earth He showed you His great fire, and you heard His words out of the fire.

Hebrews 12:25
See to it that you do not refuse Him who speaks. For if the people did not escape when they refused Him who warned them on earth, how much less will we escape if we reject Him who warns us from heaven?

Exodus 19:9
The LORD said to Moses, "Behold, I will come to you in a dense cloud, so that the people will hear when I speak with you, and they will always put their trust in you." And Moses relayed to the LORD what the people had said.

Exodus 19:19
And as the sound of the ram's horn grew louder and louder, Moses spoke and God answered him in the thunder.

Exodus 20:18
When all the people witnessed the thunder and lightning, the sounding of the ram's horn, and the mountain enveloped in smoke, they trembled and stood at a distance.

Exodus 20:22
Then the LORD said to Moses, "This is what you are to tell the Israelites: 'You have seen for yourselves that I have spoken to you from heaven.

Deuteronomy 4:33
Has a people ever heard the voice of God speaking out of the fire, as you have, and lived?

Deuteronomy 8:5
So know in your heart that just as a man disciplines his son, so the LORD your God disciplines you.

Nehemiah 9:13
You came down on Mount Sinai and spoke with them from heaven. You gave them just ordinances, true laws, and good statutes and commandments.

Out of heaven he made you to hear his voice, that he might instruct you: and on earth he showed you his great fire; and you heard his words out of the middle of the fire.