Jephthah a Legitimate Son. The mother of Jephthah was “a prostitute woman,” not meaning, however, that Jephthah was born of prostitution or was illegitimate. His mother had been a prostitute prior to her marriage as a secondary wife to Gilead, just as Rahab had once been a prostitute but later married Salmon. (Jg 11:1; Jos 2:1; Mt 1:5) That Jephthah was not illegitimate is proved by the fact that his half brothers by Gilead’s primary wife drove him out so that he would not share in the inheritance. (Jg 11:2) Additionally, Jephthah later became the accepted leader of the men of Gilead (of whom Jephthah’s half brothers seemed to be foremost). (Jg 11:11) Moreover, he offered a sacrifice to God at the tabernacle. (Jg 11:30, 31) None of these things would have been possible for an illegitimate son, for the Law specifically stated: “No illegitimate son may come into the congregation of Jehovah. Even to the tenth generation none of his may come into the congregation of Jehovah.”​—De 23:2.

Israel gathered its forces at Mizpah. The half brothers of Jephthah were evidently prominent among the older men of Gilead. (Jg 10:17; 11:7) They saw the need for proper leadership and direction. (Jg 10:18) They realized that they must be under the headship of a God-appointed man if they were to defeat Ammon. (Jg 11:5, 6, 10) Undoubtedly Jephthah and his men had been performing exploits in Tob, suggesting that he was God’s designated choice. (Jg 11:1) The men of Gilead decided to go to Jephthah, whom they had despised, to ask him to be their head.