Exodus 20:7

The third commandment is concerning the manner of our worship: where we have, 1st, A strict prohibition. Thou shalt not take the name of the Lord thy God in vain Supposing that, having taken Jehovah for their God, they would make mention of his name, this command gives a caution not to mention it in vain, and it is still as needful as ever. We take God's name in vain, 1st, By hypocrisy, making profession of God's name, but not living up to that profession. 2d, By covenant-breaking. If we make promises to God, and perform not to the Lord our vows, we take his name in vain. 3d, By rash swearing, mentioning the name of God, or any of his attributes, in the form of an oath, without any just occasion for it, to no good purpose, or to no good. 4th, By false swearing, which some think is chiefly intended in the letter of the commandment. 5th, By using the name of God lightly and carelessly. The profanation of the form of devotion is forbidden, as well as the profanation of the forms of swearing; as also, the profanation of any of those things whereby God makes himself known. For the Lord will not hold him guiltless Magistrates, that punish other offences, may not think themselves concerned to take notice of this; but God, who is jealous for his honour, will not connive at it. The sinner may perhaps hold himself guiltless, and think there is no harm in it; to obviate which suggestion, the threatening is thus expressed, God will not hold him guiltless. But more is implied, that God will himself be the avenger of those that take his name in vain; and they will find it a fearful thing to fall into the hands of the living God.