Deuteronomy 4:36

And the LORD said unto Moses, Lo, I come unto thee in a thick cloud, that the people may hear when I speak with thee, and believe thee for ever. And Moses told the words of the people unto the LORD.

And all the people saw the thunderings, and the lightnings, and the noise of the trumpet, and the mountain smoking: and when the people saw it, they removed, and stood afar off. And they said unto Moses, Speak thou with us, and we will hear: but let not God speak with us, lest we die. And Moses said unto the people, Fear not: for God is come to prove you, and that his fear may be before your faces, that ye sin not. And the people stood afar off, and Moses drew near unto the thick darkness where God was. And the LORD said unto Moses, Thus thou shalt say unto the children of Israel, Ye have seen that I have talked with you from heaven.

And the glory of the LORD abode upon mount Sinai, and the cloud covered it six days: and the seventh day he called unto Moses out of the midst of the cloud.

Did ever people hear the voice of God speaking out of the midst of the fire, as thou hast heard, and live?

Thou camest down also upon mount Sinai, and spakest with them from heaven, and gavest them right judgments, and true laws, good statutes and commandments:

For ye are not come unto the mount that might be touched, and that burned with fire, nor unto blackness, and darkness, and tempest,