Exodus 20:7

In vain. The word thus translated means “iniquity,” “falsehood,” “vanity,” “emptiness.” To inculcate reverence is the chief purpose of the third commandment (see Ps. 111:9; Eccl. 5:1, 2), which is an appropriate sequel to the two that precede it. Those who serve none but the true God, and serve Him in spirit and in truth, will avoid any careless, irreverent, or unnecessary use of the holy name. They will not indulge in profanity. Profanity, or any careless language for that matter, not only violates the spirit of religion but indicates a lack of breeding and gentlemanliness as well.

“Immodest words admit of no defence,

For want of decency is want of sense.”

This commandment applies not only to words we should avoid but to the care with which we should use those that are good (see Matt. 12:34-37).

The third commandment also condemns empty ceremony and formality in worship (see 2 Tim. 3:5), and exalts worship in the true spirit of holiness (John 4:24). It shows that obedience to the letter of the law is not sufficient. None ever reverenced the name of God more strictly than did the Jews, who to this day will not utter it. As a result, no one now knows how it should be pronounced. But in their extreme devotion to the letter of the law the Jews offered God an empty honor. This false zeal did not prevent the tragic mistake of the Jewish nation 2,000 years ago (John 1:11; Acts 13:46).

The third commandment also forbids false swearing, or perjury, which has always been considered a serious moral and social offense deserving of the most severe punishment. The careless use of God’s name denotes a lack of reverence for Him. If our thinking is on a spiritually elevated plane, our words will also be elevated, and will be dictated by what is honest and sincere (Phil. 4:8).