v1-3: Jephthah's background is described.
There is a clear similarity with Christ; he was born of a prostitute (a similar accusation was made against Christ, John 8.41); he was rejected by his family (John 1.11), he was joined by despised men (1 Cor 1.27-28). God delights to use such people, "that no flesh should glory in His presence". Jephthah is also like Abimelech; born of a concubine, at odds with his brothers; but Jephthah maintained a life of integrity, unlike Abimelech’s self-centred life.
Jephthah had settled in Tob, about 80 miles from Gilead, outside the land occupied by Israel. Like David later, the man chosen by God was rejected by men. His raiding parties ("group of adventurers) probably protected villages for money ( as in 1 Sam 25).
v4-5: As in 10.7-9, the Ammonites had attacked the area east of Jordan.
v6-7: Jephthah saw the people's motives; they only wanted him when there was a problem. Many seek Christ only when they have problems. The danger is that, once the problem is dealt with, they turn away from Him. Compare 10.11-14; the heart of man is fickle. Jephthah speaks like the Lord Himself here.
v8-11: The covenant between Gilead and Jephthah; "Will I really be your head?"; Jesus Christ must be Saviour and Lord. Jephthah did not want to be rejected immediately after delivering Gilead, so he pressed them into the covenant.
There is a prophecy too regarding Israel's acceptance of Christ after His return; such illustrations are found throughout Scripture (e.g; Joseph, David), and remind us of the unity of Scripture.
v12-13: Jephthah attacked first by words. The attack was seen as personal, "against us...our country". The Lord Jesus treats attacks against His people as attacks upon Himself.
Ammon's argument was not correct, Num 21.21-26 refers; in Deut 2.19, Israel was instructed to leave Ammon alone. Jephthah responded by use of Scripture, and possibly verbal tradition also, which he regards, quite rightly, as accurate.
v14-27: Jephthah gave a very detailed response.
v15: The summary and conclusion; Israel did not take the land being disputed.
v16: The arrival at Kadesh is in Num 20.1
v17: The representation made to Edom (Num 20.14-17) was refused (Num 20.18-21).
v18: Israel journeyed around Edom and Moab, Num 21.1-20.
v19-20: The approach to Sihon, King of the Amorites, Num 21.21-23.
v21-22: The defeat of Sihon, Num 21.24-25. Israel occupied the land as far as the fortified border of Ammon(Num 21.24), which land had been previously captured by Sihon. At that time there was no battle between Israel and Ammon.
v23: The reality of the situation was that Israel had driven out the Amorites, not the Ammonites.
v24: The background spiritual issue; God gave Israel the land. Later David used a similar argument against Goliath. The faithful Israelite would have trusted in the Lord God against any other god.
v25: The reference to Balak, who had attacked Israel, Num 22-25.
v26: Heshbon, the city of Sihon, had been occupied by Israel for 300 years. Why should Ammon have waited so long to repossess it, if their claim had been genuine. Why had they not approached Moses or Joshua? The reality was that they had waited for Israel to become vulnerable before they attacked.
v27: As in v24, Jephthah ultimately relied upon God.
v28: Predictably, Ammon rejected Jephthah's explanation.
v29: As Ammon attacked, the Spirit of the Lord came upon Jephthah. He called men from throughout Gilead and Manasseh to join him. These were the people who had asked him to be their leader, v5-6.
v30-31: Jephthah made a vow to God. This came from his confidence in God, that there would be victory; "when I return in triumph"
Many suggest this to be a rash vow, in zeal without wisdom. He had been influenced by Canaanites who sacrificed their children; the prevailing idolatrous religion had corrupted his thinking. This does not fit with the narrative here, nor with Israel's religion, even in their disobedience.
Others in Scripture who made rash vows; Herod (Mark 6.22-23), Esau (Gen 25.29-34), Elijah (1 Kings 19.1-10), Jonah (Jon 4.1-8), Peter (Matt 26.31-35). Scripture has things to say about making promises; Eccl 5.2-6; Matt 12.36-37; James 1.19.
Alternatively, here was a man of measured speech, who negotiated carefully with a Gentile king, and upon whom the Spirit of God had fallen. The words translated "offer" and "burnt offering" is ALAH, meaning "to go up"; the final phrase of v31 is therefore, "I will cause to go up that which goes up"; this may refer to consecration with death, compare Lev 27. An Israelite would not have sacrificed, by death, any person.
v32-33: Jephthah led Israel in victory over Ammon.
v34-40: Since Jephthah's daughter came out to him with dancing and thanksgiving, he had to set her apart as a virgin. Jephthah would have no grandchildren, hence his sorrow. Had a clean animal come out, then he would have offered it as a burnt offering.
The young women became a living sacrifice, a testimony to God's faithfulness to Jephthah.