Matthew Poole and continuators on Judges 12:6

6 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.

Which signifies a stream or river, which they desired to pass over: so it was a word proper for the occasion, and gave them no cause to suspect the Design, because they were required onely to express their desire, to go over the Shibboleth or River.

It is well known, that not only divers Nations, but divers Provinces, or parts of the same Nation who use the same Language, differ in their dialect and manner of pronunciation.

Or rather, he did not frame or direct himself to speak so, or to speak right; i. e. So as he was required to do it. The Hebrew Text doth not say that he could not do it, but that he did it not, because he suspecting not the design of it, uttered it speedily according to his manner of Expression.

Not in that place, at the passages of Iordan, but in that Expedition, being slain either in the Battel, or in the Pursuit, or at Iordan.