Judges 12:5-6

And the Gileadites took control of the crossing places of the Jordan opposite Ephraim. And it happened whenever any of the survivors of Ephraim said, “Let me cross over,” that the men of Gilead would say to him, “Are you an Ephraimite?” If he said, “No,” then they would say to him, “Just say, ‘Shibboleth.’ ” But he said, “Sibboleth,” for he was not prepared to pronounce it correctly. Then they seized him and slaughtered him at the crossing places of the Jordan. So at that time forty-two thousand from Ephraim fell.