“An old Jewish teaching compares the tongue to an arrow. “Why not another weapon, a sword? for example?” one rabbi asks. Because, he is told, if a man unsheathes his sword to kill his friend, and his friend pleads with him and begs for mercy, the man may be modified and returned the sword to its scabbard. But an arrow, once it is shot, cannot be returned, no matter how much one wants to.
The rabbi’s comparison is more than a metaphor. Because words can be used to inflict devastating and irrevocable suffering, Jewish teachings go so far as to compare cruel words to murder. A penitent thief can return the money he has stolen; a murderer, no matter how sincerely he repents, cannot restore his victim to life. Similarly, one who damages another's reputation through malicious gossip, or who humiliates another publicly, can never fully undo the damage.” (Joseph Telushkin, Words That Hurt Words that Heal, 1996, p.xx)