Judges 12:5-6

And the Gileadites took the passages of the Jordan from Ephraim; and it was such that when any of those of Ephraim who had escaped would say, May I pass? The men of Gilead would ask them, Art thou an Ephrathite? If he said, No; then they would say unto him, Now say Shibboleth. {Heb. a flowing stream} And he would say Sibboleth; {Heb. an ear of wheat} for he could not pronounce it the same. Then they would take him and slay him at the passages of the Jordan. And at that time forty-two thousand of those of Ephraim fell.