Āfāt al-lisān: The harms of the tongue
Al-Ghazali gave a long book of his Revival to what speech does to a person. Talking feels free, so people guard their money and their hands far more carefully than their words. A sentence that takes half a second to say can stay with a person for years.
When the heart is sound, the whole body is sound: speech carries what is already inside
The Prophet said the whole body follows one piece of flesh, the heart. Harsh words rarely begin at the mouth; they begin as resentment or contempt carried quietly for weeks. Correcting the words alone treats the symptom and leaves the illness, so attention goes back to what a person keeps feeding inside.
Ḥilm: Staying steady when provoked
The tradition links anger to fire, and the Prophet told an angry man to sit down or wash with water. Those are plain physical steps for a moment when a person has stopped thinking clearly. Words spoken in that heat come out fastest and cut deepest, and they cannot be pulled back once the heat passes.
Ghība: Backbiting
Speaking about someone in words they would hate to hear. The Quran compares it to eating a dead brother's flesh, which shows how seriously it is taken. Almost none of it feels like cruelty at the time, it feels like conversation, which is why it spreads before anyone means it to.
Ṣamt: Silence
Holding back speech on purpose, one of the oldest disciplines on the path. The Prophet said a person should speak well or stay quiet, which rules out the wide middle ground of remarks made only to fill the air. Much of the harm lives there, and a few seconds of quiet is usually enough for the urge to pass.
Murāqaba: Keeping watch
Living with the sense that you are seen and heard at every moment. People already speak more carefully when someone they respect walks into the room, and this keeps that same care when nobody is around. The pause it creates is short, about one breath before answering, and most of the words that would have hurt someone never get past it.