Jephthah's vow

Judges 11:29-40
After the victory and its tragic aftermath.
Jephthah's vow is an indication of how little the Israelites understood God at this time. Human sacrifice might please the heathen(異教徒) gods, but never the God of Israel (Abraham had learnt this long before, and God's law forbade it, Deuteronomy 12:31).
Yet, though ignorant and mistaken, the vow was made in good faith: Jephthah would forfeit(喪失) ' whatever' (person or animal ) came out of the house first. And he kept his word, though it cost him his only child, and his daughter her life.
Why?
Since Jephthah comes onto the scene as an illegitimate (非法的) outcast(棄兒), he is not one to take home or family for granted. His heartbreak is genuine(真誠). And his daughter's response is astonishing: she will not have him break faith with God on her account.
But how can a moral God associate himself with actions like this - with people like Jephthah, Samson and the rest?
We certainly cannot discount the fact that the 'heros' of Judges are people of their age - an age which the bible plainly shows was one of religious decline, failing far short of the standards set out in God's law. God acts through men and women, by definition imperfect.
These people are not set up as models: their failures, weaknesses and immorality are simply recorded, not glorified, condoned(縱容) or glossed over(輕輕带过). Only their faith and courage are commended. God does not remove himself or turn a deaf ear to a cry for help, even in an age of seemingly hopeless decadence(衰落). He acts, despite the lack of 'suitable' people. And because he acts, a 'drk age' like that of the Judges may be followed by a time of real spiritual advance.
How?
Do not make a vow before the Lord, say the truth.