Jephthah's cry, "I have opened my mouth unto Jehovah, and I cannot go back," reveals the immense gravity he placed on his spoken vow. Commentators explain that in ancient Israel, a verbal vow was considered absolutely binding. One scholar highlights the distinction between a simple vow and an irrevocable "ban" (cherem), which Jephthah likely believed he had made, leaving him feeling tragically trapped by his own words.