XXIX.  It is especially desirable that attention should be given to the case of persons in power who threaten on oath to do some hurt to those under their authority.  The remedy is twofold.  In the first place, let them be taught not to take oaths at random:  secondly, not to persist in their wicked determinations.  Any one who is arrested in the design of fulfilling an oath to injure another ought to shew repentance for the rashness of his oath, and must not confirm his wickedness under the pretext of piety.  Herod was none the better for fulfilling his oath, when, of course only to save himself from perjury, he became the prophet’s murderer. Matt. xiv. 10.  Swearing is absolutely forbidden, Matt. v. 34. and it is only reasonable that the oath which tends to evil should be condemned.  The swearer must therefore change his mind, and not persist in confirming his impiety.  Consider the absurdity of the thing a little further.  Suppose a man to swear that he will put his brother’s eyes out:  is it well for him to carry his oath into action?  Or to commit murder? or to break any other commandment?  “I have sworn, and I will perform it,” Ps. cxix. 106. not to sin, but to “keep thy righteous judgments.”  It is no less our duty to undo and destroy sin, than it is to confirm the commandment by immutable counsels.