Judges 12:5-6

12:5 The Gileadites captured the fords of the Jordan River opposite Ephraim. Whenever an Ephraimite fugitive said, “Let me cross over,” the men of Gilead asked him, “Are you an Ephraimite?” If he said, “No,” 12:6 then they said to him, “Say ‘Shibboleth!’” If he said, “Sibboleth” (and could not pronounce the word correctly), they grabbed him and executed him right there at the fords of the Jordan. On that day forty-two thousand Ephraimites fell dead.