What does Judges 3:13 mean?
Once again, Israel is participating in sin and evil. This time, the writer of Judges doesn't specify exactly what evil the Israelites are committing. It's safe to assume it follows the pattern of worshiping and serving the gods of the Canaanites (Judges 3:12).Once again, the Lord acts to express His anger and hold Israel accountable for breaking their covenant with Him. This time, the Lord strengthens an ancient relative of Israel. The Moabites are descended from Abraham's nephew Lot (Genesis 19:36–37). God strengthens the political might and will of the king of Moab to defeat Israel. He does so by joining forces with the Ammonites and Amalekites to attack the Israelites.
The Ammonite people, located to the east of the Promised Land, are also descended from Lot (Genesis 19:36–38), giving them a natural connection to the Moabites. The Amalekites were longtime enemies of Israel (Deuteronomy 25:17–19) to the south and east. Working together, the three nations were able to overcome and defeat Israel's forces and make the people slaves once again.
This verse adds that Moab took possession of "the city of palms," a name used to describe the fallen walled city of Jericho (Deuteronomy 34:3; Judges 1:16). A new city had been built on or near that spot, despite Joshua's curse (Joshua 6:26). Apparently, the king of Moab liked to rule from there at times.