Israel came to Mt. Sinai and were commanded not to come near it. There was thunder, lightning, a trumpet blast, smoke, and the mountain shook as the trumpet sounded louder and the Lord came down in fire and gave Moses the Ten Commandments.
Key points
You shall not: Have other gods; make idols; misuse God's name
You shall: keep the sabbath; honour parents
You shall not: murder; commit adultery; steal; covet