20:18-21 This law, which is so extensive that we cannot measure it, so spiritual that we cannot evade it, and so reasonable that we cannot find fault with it, will be the rule of the future judgment of God, as it is for the present conduct of man. If tried by this rule, we shall find our lives have been passed in transgressions. And with this holy law and an awful judgment before us, who can despise the gospel of Christ? And the knowledge of the law shows our need of repentance. In every believer's heart sin is dethroned and crucified, the law of God is written, and the image of God renewed. The Holy Spirit enables him to hate sin and flee from it, to love and keep this law in sincerity and truth; nor will he cease to repent.

18-21. all the people saw the thunderings and the lightnings—They were eye and ear witnesses of the awful emblems of the Deity's descent. But they perceived not the Deity Himself.