Deuteronomy 4:12
And the LORD spoke to you out of the fire. You heard the sound of the words, but saw no form; there was only a voice.
Berean Standard Bible
And the LORD spake unto you out of the midst of the fire: ye heard the voice of the words, but saw no similitude; only ye heard a voice.
The LORD spoke to you out of the middle of the fire: you heard the voice of words, but you saw no form; you only heard a voice.