What does Judges 11:23 mean?
Jephthah, the brand-new leader of the Israelite people in Gilead, has sent a long message to the king of Ammon. The missive included a history lesson correcting the king's wrongful claim. The Ammonite leader claimed that Gilead was territory taken from his people by Israel during the time of Moses. Jephthah has shown that there were not Ammonites in Gilead when Moses arrived—the inhabitants were Amorites. The Israelites took it over after the Amorites attacked and were defeated (Judges 11:14–22).This verse contains the heart of Jephthah's argument: God gave this land to Israel when He gave them victory over the Amorites. The fact that Israel had possessed the land, for centuries (Judges 11:26) was evidence that it was the Lord's divine will for Israel to have it. Jephthah poses a challenging question to the Ammonite king: are you going to try and take from Israel what God has given them?
Another way to phrase this part of Jephthah's message is that Ammon's argument is with God Himself, not with Israel or any other leader. The Israelites living in Gilead have simply received what the Lord has given to them. Who are the Ammonites to defy the Lord God in this way? Jephthah will continue by highlighting the fact that no one has thought to dispute the territory from Moses until now.