So Jephthah passed over unto the children of Ammon, to fight against them,.... As in Judges 11:29, after he had made the above vow:

and the Lord delivered them into his hands; when both armies met and engaged, victory was on the side of Jephthah; the Lord being with him, and giving him success, to where all is justly ascribed.

After seeking to ensure the help of the Lord by this vow, he went against the Ammonites to fight against them; and the Lord delivered them into his hand, so that Jephthah smote them in a very great slaughter "from Aror (or Nahr Ammn; see Judges 11:26) to the neighbourhood of ('till thou come to;' see at Genesis 10:19) Minnith, (conquering and taking) twenty cities, and to Abel Keramim (of the vineyards)." Minnith, according to the Onom. (s. v. Mennith), was a place called Manith in the time of Eusebius, four Roman miles from Heshbon on the road to Philadelphia, with which the account given by Buckingham of the ruins of a large city a little to the east of Heshbon may be compared (see v. Raum. Pal. p. 265). The situation of Abel Keramim (plain of the vineyards: Luther and Eng. Ver.) cannot be determined with the same certainty. Eusebius and Jerome mention two places of this name (Onom. s. v. Abel vinearum), a villa Abela vinetis consita (κώμη ἀμπελοφόρος Ἄβελ) seven Roman miles from Philadelphia, and a civitas nomine Abela vini fertilis twelve Roman miles to the east of Gadara, and therefore in the neighbourhood of the Mandhur. Which of the two is referred to here remains uncertain, as we have no precise details concerning the battle. If the northern Abela should be meant, Jephthah would have pursued the foe first of all towards the south to the neighbourhood of Heshbon, and then to the north to the border of Bashan. Through his victory the Ammonites were completely subdued before the Israelites.

So Jephthah passed over unto the children of Ammon to fight against them; and the LORD delivered them into his hands.

Jud 11:32, 33. He Overcomes the Ammonites.

32. Jephthah passed over unto the children of Ammon . and the Lord delivered them into his hands-He met and engaged them at Aroer, a town in the tribe of Gad, upon the Arnon. A decisive victory crowned the arms of Israel, and the pursuit was continued to Abel (plain of the vineyards), from south to north, over an extent of about sixty miles.

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.