Deuteronomy 4:12

4:12 Then the Lord spoke to you from the middle of the fire; you heard speech but you could not see anything – only a voice was heard.

Deuteronomy 4:33

4:33 Have a people ever heard the voice of God speaking from the middle of fire, as you yourselves have, and lived to tell about it?

tn The words “was heard” are supplied in the translation to avoid the impression that the voice was seen.