Judges 12:5-6

5The Gileadites 1captured the fords of the Jordan opposite Ephraim. And it happened when any of the fugitives of Ephraim said, “Let me cross over,” the men of Gilead would say to him, “Are you an Ephraimite?” If he said, “No,” 6then they would say to him, “Say now, ‘Shibboleth.’” But he said, “Sibboleth,” for he could not 2pronounce it correctly. Then they seized him and slew him at the fords of the Jordan. Thus there fell at that time 42,000 of Ephraim.