Deuteronomy 5:4-5
5:4 The Lord spoke face to face with you at the mountain, from the middle of the fire.
5:5 (I was standing between the Lord and you at that time to reveal to you the message of the Lord, because you were afraid of the fire and would not go up the mountain.) He said:
Exodus 19:19
19:19 When the sound of the horn grew louder and louder, Moses was speaking and God was answering him with a voice.