Exodus 19:9 The LORD 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 the LORD.

Exodus 19:19 When the sound of the trumpet grew louder and louder, Moses spoke and God answered him with thunder.

Exodus 20:18 All the people perceived the thunder and the lightning flashes and the sound of the trumpet and the mountain smoking; and when the people saw it, they trembled and stood at a distance.

Exodus 20:22 Then the LORD said to Moses, "Thus you shall say to the sons of Israel, 'You yourselves have seen that I have spoken to you from heaven.

Deuteronomy 4:33 "Has any people heard the voice of God speaking from the midst of the fire, as you have heard it, and survived?

Deuteronomy 8:5 "Thus you are to know in your heart that the LORD your God was disciplining you just as a man disciplines his son.

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

Hebrews 12:25 See to it that you do not refuse Him who is speaking. For if those did not escape when they refused him who warned them on earth, much less will we escape who turn away from Him who warns from heaven. (NASB ©1995)