A man had three daughters, and each carried a flaw. The first was a thief who could not keep her hand from what was not hers. The second was lazy and refused the work a household required. The third was a slanderer whose tongue wounded anyone it touched.
Despite their reputations, a neighbor came and asked for all three as brides for his three sons. He knew exactly what he was taking on, and he believed his sons could steady them. The weddings were celebrated, and the daughters went to their new home.
Some months later, the father came to visit and see how his daughters were faring. The first two praised their father-in-law generously. He had covered for the thief, covered for the sluggard, and made their lives comfortable. The third daughter, however, began to whisper terrible things about him. She insisted he had made advances, that his kindness hid a predator's intention.
Her father did not fully believe her, but his doubt was already poisoned. She invited him to hide in the inner room and see for himself. When her father-in-law walked in and greeted her with the usual kiss on the forehead that had always passed between them, she cried out, "Be careful, my father is here." The sentence was designed to make an innocent greeting look like a guilty secret.
Her father, watching from hiding, misread what he saw. Rage took him, and he killed his son-in-law on the spot. The sons of the household heard the commotion and killed the father in return.
Four lives, ended in an afternoon, because of one tongue. The sages draw the moral directly: lashon hara, the evil tongue, kills three at once, the speaker, the listener, and the person slandered. This story shows that sometimes the body count is higher than three (Gaster, Exempla No. 142).