Charles Ellicott Commentary Judges 11:40

"that the daughters of Israel went yearly to celebrate the daughter of Jephthah the Gileadite four days in a year." — Judges 11:40 (ASV)

To lament. —Rabbi Tanchum makes it mean “to praise,” or “celebrate.” The feelings of the Israelites towards Jephthah’s daughter would be much the same as that of the Romans towards Claelia, and of other nations towards heroines whose self-sacrifice has helped them to victory.