This commandment was given to protect one's name and reputation. Communicating in ways that do not uphold our neighbor's name and reputation break this commandment. The greatest violators are false preachers who, by their false doctrine, speak ill of God and his name. If we are aware of something negative about our neighbor, but have no authority to act, we should remain silent and not speak of it. However, when the proper authorities call upon us to speak to the matter, we will do so honestly. Also, if we are aware of something that requires the attention of public authorities, we will share it with them. Luther clearly states that civil magistrates, pastors, and parents must act upon hearing of something requiring their attention. Luther carefully distinguishes between secret sins and open, public sins. Secret sins should not be made public. However, when the error is open we have every right, even the duty, to speak publicly about it and to testify against the person involved. Speaking publicly about another person's public error or sin is not bearing false witness, nor is it a violation of Matthew 18. In his Large Catechism, Luther concludes that putting "the best construction on everything" is a fine and noble virtue.