Matthew Poole and continuators on Judges 9:41

41 And Abimelech dwelt at Arumah ; and Zebul thrust out Gaal and his brethren , that they should not dwell in Shechem.

He did not prosecute his Victory, but retreated to Arumah, partly to see the effect of this Fight, and whether the Shechemites would not of themselves return to his Government, being either perswaded by Zebul upon this occasion, or terrified by his strength and valour, or now by his clemency in proceeding no further against them: and partly, that being hereby grown more secure, he might have the greater advantage against them, which accordingly he here makes use of.

Which he was inabled to do, because the Multitude, which is generally light and unstable, and judgeth of all things by Events, were now enraged against Gaal, suspecting him guilty either of Treachery, or Cowardize, or ill Conduct: and besides, they thought the expulsion of Gaal would sweeten and satisfie Abimelech, and make him give over the War against them. But though they were offended with Gaal, yet Zebul's interest was not so considerable with them, that he could prevail with them either to kill Gaal and his Brethren, or to yield themselves to Abimelech; and therefore he still complies with the People, and waits for a fairer opportunity, though in vain.