6 they would tell him to say "Shibboleth." If he was from Ephraim, he would say "Sibboleth," because people from Ephraim cannot pronounce the word correctly. Then they would take him and kill him at the shallow crossings of the Jordan. In all, 42,000 Ephraimites were killed at that time.
Matthew Henry's Commentary on Judges 12:6
Commentary on Judges 12:1-7
(Read Judges 12:1-7)
The Ephraimites had the same quarrel with Jephthah as with Gideon. Pride was at the bottom of the quarrel; only by that comes contention. It is ill to fasten names of reproach upon persons or countries, as is common, especially upon those under outward disadvantages. It often occasions quarrels that prove of ill consequence, as it did here. No contentions are so bitter as those between brethren or rivals for honour. What need we have to watch and pray against evil tempers! May the Lord incline all his people to follow after things which make for peace!