Judges 12:5-6

The men of Gilead captured the crossing places of the Jordan River. Those places led to the country of Ephraim. A man 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 said, “No,” they would say to him, “Say the word ‘Shibboleth.’” The men of Ephraim could not say that word correctly. They pronounced it “Sibboleth.” If the man from Ephraim said, “Sibboleth,” the men of Gilead would kill him at the crossing place. So 42,000 men from Ephraim were killed at that time.