What is the aim of the ninth commandment?

That I never give false testimony against anyone, twist no one's words, not gossip or slander, nor join in condemning anyone rashly or without a hearing.¹ Rather, in court and everywhere else, I should avoid lying and deceit of every kind; these are the very devices the devil uses, and they would call down on me God's intense wrath.² I should love the truth, speak it candidly, and openly acknowledge it.³ And I should do what I can to guard and advance my neighbor's good name.⁴