Judges 9:22-25

22After Abimelech had reigned over Israel for three years, 23God sent a spirit of animosity1 between Abimelech and the leaders of Shechem and caused them to treat Abimelech deceitfully, 24in order that the crime against the seventy sons of Jerubbaal might come to justice and their blood be avenged on their brother Abimelech and on the leaders of Shechem, who had helped him murder his brothers.

25The leaders of Shechem set up an ambush against Abimelech on the hilltops, and they robbed all who passed by them on the road. So this was reported to Abimelech.