What does the Ninth Commandment forbid?

The Ninth Commandment forbids lying and slandering, which directly speaks to the importance of truthfulness in speech and the integrity of a person's reputation. This commandment emphasizes the moral obligation to be honest and not to deceive others through false statements or harmful gossip. In the context of the catechism, it serves to uphold the trust and reliability essential in personal relationships and within society at large.

Maintaining honesty not only protects individual reputations, but it also fosters a community built on trust, where people can rely on each other's words. By forbidding slander, the commandment also highlights the ethical responsibility to refrain from speaking ill of others in ways that may unjustly damage their standing or character. Overall, the Ninth Commandment affirms the value of speaking the truth and respecting the dignity of others.