In Irish mythological history, the Tuatha Dé Danann are described as a tribe of people with certain supernatural powers. It is believed that, prior to Christian contact, the Tuatha Dé were actually gods, but they were demoted to historical people, predecessors, when the theological climate of Ireland changed.
The story of Jephthah and his daughter reminded me, in a way, of the Tuatha Dé – in that I saw in them some vestiges of gods made human, perhaps as the Israelites moved toward monotheism and the area around Mizpah was assimilated.
It starts with Jephthah being a son of Gilead. This isn’t presented as some nationalist descriptor, in the sense that a U.S. citizen might be described as a “son of America.” Rather, it seems that he is seen as an actual literal son. It’s not uncommon in polytheistic tribal societies personify the tribe as a whole as a single figure or god. Perhaps there was originally a cult of Gilead in the region, of whom Jephthah was a son and lesser god.
We see this in Genesis where nearly all of the characters appear to be tribal archetypes, and the twelve tribes of Israel are shown to be actual, literal, brothers. I think that there is evidence to suggest to that Judges may be sourced from an older tradition where this personification was still practised, namely the slip in Judges 1:3 where Judah is, for a few sentences, a single character.
There is also often a process of borrowing and trading in religion, where stories might be, over time, attributed to new gods as they spread from place to place. It’s a bit of a stretch, but Jephthah’s refusal to help the Gileadites against the Ammonites without a promise that, if successful, he would be made their leader reminds me of Marduk’s own similar deal when asked to defeat Tiamat, told in the Enuma Elish. Parallels between Genesis and the Enuma Elish have been fairly thoroughly discussed, so I don’t think it’s taking too much of a liberty to say that, at the very least, there was a good deal of sharing between the two cultures.
Then there is Jephthah’s daughter. It seems that Jephthah’s story was included in Judges to explain the origins of a festival in which the women of Israel would spend four days in mourning over his daughter – both her life and, tellingly, her virginity. The tragedy of the story appears to be that she will not bear children – not that she is barren, but that she has not been “ploughed.”
This makes sense if, as J.R. Porter argues, her festival “marked the death of the spirit of fertility during the dry season” (The New Illustrated Companion to the Bible, p. 69). The fact that she is a virgin, rather than barren, leaves open the possibility of fertility and future pregnancy.
In this sense, Jephthah’s daughter might be a Persephone-like character. Unlike Jephthah’s daughter, Persephone is kidnapped by death (Hades), leading to her mother, Demeter – a harvest goddess – to stop nurturing the land, bringing winter. Through an elaborate story, a deal is eventually struck allowing Persephone to return home for some parts of the year (Spring and Summer) so long as she returns to the Underworld the rest of the year (Autumn and Winter).
In this case, it is her parent himself who sends her to death, though the motif of honouring a vow/deal is still present.
I want to make clear that this is pure on-the-fly conjecture on my part, but I find it interesting to think that Jephthah’s story may have originally been a regional mythic cycle in which a seasonal, civilizing deity conquers the forces of evil but, in exchange, must give up fertility (as his only child, Jephthah’s daughter is the vehicle for Jephthah’s family line’s continuance), bringing in the lean months of winter.
As the cult of YHWH spread and, over time, became monotheistic, local deities were preserved as historical heroes, Jephthah and his daughter among them.