Right speech is more demanding than "do not lie." The early discourses name four unwholesome forms: false speech, divisive speech, harsh speech, and idle or useless chatter. Their positive counterparts are truthfulness, speech that reconciles, gentle speech, and words spoken meaningfully at the proper time.
Truth alone is not the only test. In MN 58, Prince Abhaya asks whether the Buddha ever speaks words displeasing to others. The Buddha rejects a simple yes-or-no trap and explains his discipline. He does not speak what is untrue or unbeneficial. When something is true and beneficial, he knows the right time to say it, whether the listener finds it pleasing or painful. Compassion governs both speech and timing.
Divisive speech takes what is heard here and repeats it there to break people apart. Right speech instead reconciles the divided and strengthens concord. Harsh speech aims to wound even when its factual content is accurate. Gentle speech is not weak agreement; it refuses hatred as the instrument of correction. Idle chatter is speech without purpose that feeds distraction, vanity, rumor, or heedlessness. Silence can be wiser, but silent complicity with harm is not automatically virtuous.
The Simile of the Saw (MN 21) gives an extreme training: even if bandits were to sever a person limb by limb, hatred would still be a failure of the Buddha's instruction. The point is not to tell victims to remain in danger. It reveals the depth of the training—another person's cruelty does not make hatred wholesome. One may leave, seek protection, tell the truth, and impose a boundary without cultivating the wish to harm.
A practical Buddhist review asks five questions: Is it true? Is it beneficial? Is this the right time? Is the mind moved by goodwill? Can the words be spoken gently and clearly? Not every conversation permits a perfect answer, but pausing long enough to ask interrupts many forms of kamma.
Prince Abhaya is coached to trap the Buddha with a question about painful speech. The Buddha uses the prince's care for the infant on his lap as a simile: one may act firmly and cause temporary discomfort to prevent greater harm, but the motivation is compassion and knowledge of benefit.
The Buddha tells the monks to train so that their minds remain free of hate even under shocking abuse. They are to pervade the aggressor and the whole world with a mind of goodwill.