You shall not take the name of the LORD your God in vain; for the LORD will not hold him guiltless that takes his name in vain.
The swearer tries to excuse himself. "I did not mean it. I was only in fun." There are some things not the proper subjects of fun. Surely a man ought not to make fun of God, or of invoking the wrath of God upon himself or others. But the swearer says: "It is a relief for me to swear. It cools off my heated spirits." Often it is the reverse, adding fuel to the flame, not only to himself, but to others, especially those he curses. But if it is a relief, what is it a relief of? It is a relief to the storm-cloud to throw out its lightnings, because it is over-charged with electricity. So it is a relief for you to throw out your cursing because you are over-charged with cursing. Your heart is so full of hatred that when stirred in anger it overflows in curses. You had far better bring such a heart to God with a strong cry for mercy. Again the swearer says: "I know it is wrong, but it is a habit I have fallen into to such an extent that I often swear without knowing it." Do you not see that habit does not excuse but rather aggravates the offence? No one can become wicked at once. Your habit only shows how often you have sinned, how far you have gone down in this kind of wickedness. Again the swearer says: "I may as well say it as think it." You should not think an oath or curse. But it is worse to speak it. The letter of the law forbids the word, and so checks the evil in the heart, and at any rate prevents its injuring others. You gain inward control by outward control. Come toward the spirit of the law, checking the thought by obeying the letter. You keep yourself also from being a curse. The swearer is a moral blight in a community, his oath-speaking is a spreading infection, he is himself a curse to others.
(F. S. Schenck.)
Parallel VersesKJV: Thou shalt not take the name of the LORD thy God in vain; for the LORD will not hold him guiltless that taketh his name in vain.