Judges 12:5-6

The men of Gilead captured the crossings of the Jordan River that led to the country of Ephraim. A person from Ephraim trying to escape would say, “Let me cross the river.” Then the men of Gilead would ask him, “Are you from Ephraim?” If he replied no, they would say to him, “Say the word ‘Shibboleth.’ ” The men of Ephraim could not say that word correctly. So if the person from Ephraim said, “Sibboleth,” the men of Gilead would kill him at the crossing. So forty-two thousand people from Ephraim were killed at that time.