Deuteronomy 4:10-13

10how on the day that you stood before the Lord your God at Horeb, the Lord said to me, 'Gather the people to me, that I may let them hear my words, so that they may learn to fear me all the days that they live on the earth, and that they may teach their children so.'

11And you came near and stood at the foot of the mountain, while the mountain burned with fire to the heart of heaven, wrapped in darkness, cloud, and gloom.

12Then the Lord spoke to you out of the midst of the fire. You heard the sound of words, but saw no form; there was only a voice.

13And he declared to you his covenant, which he commanded you to perform, that is, the Ten Commandments, and he wrote them on two tablets of stone.