An oath to the Lord

Judges
I think today's reading Judges (particularly chapter 11) gives us a pretty clear message on vows.  Don't make them too lightly!  Jephthah, a warrior from Gilead of the Israelites, made a vow that if God was with him in battle and he returned home in victory, he would sacrifice as a burnt offering the first thing he laid eyes on when he got home.
Lo and behold, his daughter, his only child, is the first thing to come out of his home.  Did he offer her as a burnt offering to the Lord?  Some say yes, he did sacrifice her.  More likely, he dedicated her to the Lord's service and she never married.  Regardless, he was not prepared to make this sacrifice.  Fortunately, he upheld his oath that he had made to the Lord, and therefore upheld his honour and the name of the Lord.
Lesson to learn?  As I mentioned, when making an oath, or vowing to do something, carry through on your promise, and realize when you're making it that a vow is not a fleeting fantasy.