‘ And God sent an evil spirit between Abimelech and the men of Shechem, and the men of Shechem dealt treacherously with Abimelech.'
Satan and his minions are ever at work, active in the sons of disobedience (Ephesians 2:2), but the former prophets had no difficulty in asserting that they were under Yahweh's control, for they believed rightly that all things were finally under His control. Such activity of an evil spirit produced animosity and enmity between Abimelech and the chief men of Shechem (compare 1 Samuel 16:14). Indeed here Yahweh is seen as active in the process. He can influence evil spirits as He influences wicked men. And it was His purpose to punish both Abimelech and the chief men.