Judges 12:5-6

And the Gileadites took the crossing-places of Jordan against the Ephraimites; and when any of the men of Ephraim who had gone in flight said, let me go over; the men of Gilead said to him, Are you an Ephraimite? And if he said, No; Then they said to him, Now say Shibboleth; and he said Sibboleth, and was not able to say it in the right way; then they took him and put him to death at the crossing-places of Jordan; and at that time forty-two thousand Ephraimites were put to death.