What does Judges 9:25 mean?
When it was convenient, the leaders of Shechem paid to help Abimelech kill his brothers (Judges 9:1–6). That let them gain control—or so it seemed—over the only son of Gideon not dead or in hiding. After only a few years, a divisive and hateful relationship has emerged. The same men who installed Abimelech as ruler now want to do him harm.To accomplish this, they devise a scheme. The ambush described here might have begun as an assassination plot. This may have been thwarted if Abimelech spent most of his time in Arumah (Judges 9:41), instead. Either as a second plan, or part of the main plot, these ambushes are used to rob people traveling near the city.
Shechem was ideally located on a trade route, bringing business through the gates in the form of merchants and goods. Abimelech would likely have benefitted from this trade through taxes and tariffs. If word got out that merchants coming in and out of Shechem were being robbed by bandits, those wishing to do business would find other places to conduct it. Anyone with goods or money would have quickly learned to avoid Shechem, directly depriving King Abimelech of his income.
More treachery will follow, leading to terrible bloodshed (Judges 9:45).