Deuteronomy 4:11-15

11“You came near and stood at the foot of the mountain, while flames from the mountain shot into the sky. The mountain was shrouded in black clouds and deep darkness.

12And the Lord spoke to you from the heart of the fire. You heard the sound of his words but didn’t see his form; there was only a voice.

13He proclaimed his covenant—the Ten Commandments—which he commanded you to keep, and which he wrote on two stone tablets.

14It was at that time that the Lord commanded me to teach you his decrees and regulations so you would obey them in the land you are about to enter and occupy.

15“But be very careful! You did not see the Lord’s form on the day he spoke to you from the heart of the fire at Mount Sinai.