That the daughters of Israel went yearly to lament the daughter of Jephthah the Gileadite four days in a year.
All Commentaries on Judges 11:40 Go To Judges 11
Ambrose of Milan
Never shall I be led to believe that the leader Jephthah made his vow otherwise than without thought, when he promised to offer to God whatever should meet him at the threshold of his house on his return. For he repented of his vow, as afterwards his daughter came to meet him. He tore his clothes and said, “Alas, my daughter, you have entangled me, you have become a source of trouble for me.” And though with pious fear and reverence he took upon himself the bitter fulfillment of his cruel task, yet he ordered and left to be observed an annual period of grief and mourning for future times. It was a hard vow, but far more bitter was its fulfillment, while he who carried it out had the greatest cause to mourn. Thus it became a rule and a law in Israel from year to year, as it says: “that the daughters of Israel went to lament the daughter of Jephthah the Gileadite four days in a year.” I cannot blame the man for holding it necessary to fulfill his vow, but yet it was a wretched necessity which could only be solved by the death of his child.…
What, then, in the case of esteemed and learned people is full of marvel, that in the case of a virgin is found to be far more splendid, far more glorious, as she says to her sorrowing father, “Do to me according to that which has proceeded out of your mouth.” But she asked for a delay of two months in order that she might go about with her companions upon the mountains to bewail fitly and dutifully her virginity now given up to death. The weeping of her companions did not move her, their grief did not prevail upon her, nor did their lamentations hold her back. She did not allow the day to pass, nor did the hour escape her notice. She returned to her father as though returning according to her own desire, and of her own will [she] urged him on when he was hesitating, and acted thus of her own free choice, so that what was at first an awful chance became a pious sacrifice.