Judges 11:39-40 KJV
And it came to pass at the end of two months, that she returned unto her father, who did with her according to his vow which he had vowed: and she knew no man. And it was a custom in Israel,
 That the daughters of Israel went yearly to lament the daughter of Jephthah the Gileadite four days in a year.
Jephthah made a vow to God that if God gave him victory in the battle against the Ammonites, on his return home he would offer whatever came out to meet him FIRST as a burnt offering to the LORD.
Now that’s a serious vow! When I read this account two things came to mind. Either this was loose talk or the guy Jephthah was too spiritual.
Couldn’t he have modified his vow maybe just a little bit? Like saying, “whichever one of his livestock that came out to meet him first…?”
Jephthah’s reaction when his daughter came out to meet him tells us how broken he was afterwards, a victor who couldn’t celebrate his victory…. A sour victory.
You are under no obligation to make a rash vow to the Lord, especially when in distress. Until u’ve come to understand the full implications of a vow, don’t just open your mouth to pronounce it. You might do better with a sacrifice instead.
Let’s be watchful with our vows, they are not mere words.
Have a blessed day.