Judges 12:5-6

The Gileadites took control of the Jordan’s crossing points into Ephraim. Whenever one of the Ephraimite fugitives said, “Let me cross,” the Gileadites would ask him, “Are you an Ephraimite?” If he said, “No,” they would tell him, “Then say shibboleth .” But he would say, “ sibboleth ,” because he couldn’t pronounce it correctly. So they would seize him and kill him at the Jordan’s crossing points. Forty-two thousand of the Ephraimites fell at that time.