If the “Spirit of the Lord” was on Jephthah, how could he make such an unwise vow (11:29–31)?
There is no connection between the Spirit’s empowering of Jephthah and his vow. Possessing the Holy Spirit for a special assignment does not guarantee a person will be faultless in other areas of life. Jephthah’s vow was an attempt to strike a deal with God for a blessing instead of trusting him. What he got instead was grief.