Large Catechism: Covering up Evil (I 59-69)

"We are not to swear in support of evil, that is, to support falsehood, or to swear when there is no need or use. But we should swear for the support of good and the advantage of our neighbor. For such swearing is truly a good work, by which God is praised, truth and right are established, falsehood is refuted, peace is made among men, obedience is rendered, and quarrels are settled. For in this way God Himself intervenes and separates right and wrong, good and evil" (66).https://wrestlingwiththeoogy.org/media/podcast/cc_260112.mp3