Wilt not thou... ? Figure of speech Erotesis. Jephthah does not recognize Chemosh as. god. The emphasis is on "thy" and "our", and is the argument a fortiori: and, taking them on their own ground, it is the argumentum ad hominem.
Related Commentaries of Judges 11:24
Judges 11:24
24 Wilt not thou possess that which Chemosh thy god giveth thee to possess? So whomsoever the LORD our God shall drive out from before us, them will we possess.