31 Then it shall be, that whatsoever  cometh forth of the doors of my house to meet me, when I return in peace from the children of Ammon, shall surely be the Lord's, and I will offer it up for a burnt offering.
31 whatever comes out of the door of my house to meet me when I return in triumph from the Ammonites will be the Lord's, and I will sacrifice it as a burnt offering."
31 then whatever
31 then I'll give to God whatever comes out of the door of my house to meet me when I return in one piece from among the Ammonites - I'll offer it up in a sacrificial burnt offering."
31 then it will be that whatever comes out of the doors of my house to meet me, when I return in peace from the people of Ammon, shall surely be the Lord's, and I will offer it up as a burnt offering."
31 I will give to the Lord whatever comes out of my house to meet me when I return in triumph. I will sacrifice it as a burnt offering."
Matthew Henry's Commentary on Judges 11:31
Commentary on Judges 11:29-40
(Read Judges 11:29-40)
Several important lessons are to be learned from Jephthah's vow. 1. There may be remainders of distrust and doubting, even in the hearts of true and great believers. 2. Our vows to God should not be as a purchase of the favour we desire, but to express gratitude to him. 3. We need to be very well-advised in making vows, lest we entangle ourselves. 4. What we have solemnly vowed to God, we must perform, if it be possible and lawful, though it be difficult and grievous to us. 5. It well becomes children, obediently and cheerfully to submit to their parents in the Lord. It is hard to say what Jephthah did in performance of his vow; but it is thought that he did not offer his daughter as a burnt-offering. Such a sacrifice would have been an abomination to the Lord; it is supposed she was obliged to remain unmarried, and apart from her family. Concerning this and some other such passages in the sacred history, about which learned men are divided and in doubt, we need not perplex ourselves; what is necessary to our salvation, thanks be to God, is plain enough. If the reader recollects the promise of Christ concerning the teaching of the Holy Spirit, and places himself under this heavenly Teacher, the Holy Ghost will guide to all truth in every passage, so far as it is needful to be understood.