Judges 12:5-6

And the Gileadites took the passages of Jordan before the Ephraimites: and it was {so}, that when those Ephraimites which were escaped said, Let me go over; that the men of Gilead said unto him, {Art} thou an Ephraimite? If he said, Nay; Then said they unto him, Say now Shibboleth: and he said Sibboleth: for he could not frame to pronounce {it} right. Then they took him, and slew him at the passages of Jordan: and there fell at that time of the Ephraimites forty and two thousand.