“ I therefore have not sinned against you, but you do me wrong to war against me. Yahweh, the Judge, be judge this day between the children of Israel and the children of Ammon.”
Jephthah then finished on a note of injured hurt. He, representing Israel, had done nothing wrong to Ammon. It was Ammon who were behaving wrongly. Thus Yahweh the righteous Judge would judge appropriately and act accordingly. Yahweh would be on his side. He no doubt trusted that Yahweh, and his own army, would note his words as well as the king of Ammon.
Note how he spoke of himself as representing the nation. He was already behaving like a king. Previously he has spoken only of ‘Israel', the term used by the king of Ammon (Judges 11:13). Now he speaks of ‘the children of Israel' because he is contrasting them with ‘the children of Ammon'.
By now, he knew, the king of Ammon would be thinking seriously. These were not the words of some frightened leader trying to bolster up his own courage, these were the words of a man of iron, who was unafraid, who was aware that Yahweh was on his side and would act for him, who was righteously indignant and who had no fear of Ammon. The king had been used to the cowering ways of the elders of Gilead when he received his tribute. Now he would realise why that tribute had recently been refused. A new man had arisen in Israel, a man of Yahweh.