There are some important differences between Jephthah’s war against the Ephraimites and his war against the Ammonites. For one, his war against the Ammonites (Judges 11:32–33) is recounted in far less detail than his war against the Ephraimites (Judges 12:1–6). Furthermore, each account reveals Jephthah’s personal motives for the respective war. His war against Ammon is motivated by his wish for status and honour (Judges 11:9–11). His war against Ephraim is motivated by his desire to defend his status (Judges 12:4). He goes into combat against those whom he delivered shortly before, and slaughters them mercilessly.
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4 Then Jephthah gathered all the men of Gilead and fought with Ephraim. And the men of Gilead struck Ephraim, because they said, “You are fugitives of Ephraim, you Gileadites, in the midst of Ephraim and Manasseh.”