 Calvin asserted that God's intent in the prohibition of false witness extended “more generally to calumny and sinister insinuations by which our neighbors are unjustly aggrieved.” Since perjury in court is amply prohibited by the third commandment (against swearing falsely), the commandment against false witness must extend to protection of one's good name.“The equity of this is perfectly clear.For if a good name is more precious than riches, a man, in being robbed of his good name, is no less injured than if he were robbed of his goods; while, in the latter case, false testimony is sometimes not less injurious than rapine committed by the hand.”
Martin Luther explained that this commandment is given “first of all that every one shall help his neighbor to secure his rights, and not allow them to be hindered or twisted, but shall promote and strictly maintain them, no matter whether he be judge or witness.” Luther also asserted that this command extends to the spiritual jurisdiction and prohibited slander against preachers and Christians by calling them heretics, apostates, seditious, wicked, etc.