If someone decides or speaks immediately while furious, repairing the harm may be difficult. Uncontrolled anger can produce insults, accusations, estrangement, or injustice. This is the kind of practical damage against which the narration warns. Pausing, listening, and postponing a heated discussion can reduce the risk.
Example 1: A teacher investigates a student’s mistake and corrects it without public humiliation.
Example 2: During a family disagreement, one chooses clear and restrained words instead of insults or ridicule.
يُفْسِدُ means “spoils or corrupts.” The narration warns about consequences for the practice of faith; it is not a declaration that an ordinary feeling of anger instantly amounts to unbelief.