It was a password designed to detect those who weren’t from Gilead. After the Gilead army had defeated the Ephraimite army, the Ephraimites were trying to get back across the river, the fords of which had been taken over by the forces of Gilead. Some really smart Gilead army guy figured out a simple way to figure out who was who. The Ephaimite dialect had no “sh” sound. So if someone trying to cross the ford was asked to say “shibboleth” and he wasn’t a good mimic and said “sibboleth,” he was killed.
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Didn’t the Americans come up with a similar test for spotting Nazis in post-WWII Germany?
Re: “Didn’t the Americans come up with a similar test for spotting Nazis in post-WWII Germany?”
Don’t know about post-war, but varios shibboleths were used by the Allies in WWII. I’ve cut’n’pasted the following from wikipedia:
During the Battle of Normandy in the Second World War, the American forces used the challenge-response codes “Flash” - “Thunder” - “Welcome”. The last response was used to identify the challenger as a native English speaker (and therefore not an enemy), whereas the German enemy would pronounce it as “Velcome”. This caused problems for German Jews serving in the U.S. Army.
Similarly during Operation Chariot the British raiders used the challenge “War Weapons Week” and the countersign “Welmouth”, likewise unpronounceable by most Germans.
In the Pacific Theatre of Operations, the shibboleth was lollapalooza, whose pronunciation produces severe difficulties for native speakers of the Japanese language (another was Lucille Ball).
Woolloomooloo was used by Australian soldiers in the Pacific Theatre during the Second World War to identify themselves when approaching a camp.