In the movie "Dogma", Archangel Metatron, played by Severus Snape Alan Rickman, serves as a "Voice of God".
Behold the Metatron, herald of the Almighty and voice of the one true God.
...
Human beings have neither the aural nor the psychological capacity to withstand the awesome power of God's true voice. Were you to hear it, your mind would cave in and your heart would explode within your chest. We went through five Adams before we figured that one out.
However, based on my somewhat limited knowledge of source material, neither of the original sources (Old Testament or Talmud) which mention Metatron ever assign him the role of a "Voice of God".
Moreover, I recall that Moses was spoken to directly, when he saw a burning bush:
So when the Lord saw that he turned aside to look, God called to him from the midst of the bush and said, "Moses, Moses!" And he said, "Here I am." Then He said, "Do not draw near this place. Take your sandals off your feet, for the place where you stand is holy ground." Moreover He said, "I am the God of your father; the God of Abraham, the God of Isaac, and the God of Jacob." And Moses hid his face, for he was afraid to look upon God. (Src: Exodus)
So, the question becomes: where did these 2 ideas originate? That:
God's voice is deadly to mortals and thus he needs an angel to speak for him as a "Voice"?
That archangel Metatron held that role (as opposed to Talmudic "Scribe of heaven")
I would be equally happy with an answer sourced from Kevin Smith or someone else familiar with that movie's creation; or with simply a reasonably well known (e.g. could possibly be known to Kevin Smith) earlier work that had the same idea(s).
NOTE: For those who demand a reason why every question was asked, I was going to compare Eru and his speaking (or not speaking) to Men on Arda to Judeo-Christian deity who must have a "Voice of God" angel. Only to promptly realize that the source material did NOT have such a notion, and the idea in my mind originated from "Dogma".