וַיִּשְׁלַ֤ח אֱלֹהִים֙ ר֣וּחַ רָעָ֔ה בֵּ֣ין אֲבִימֶ֔לֶךְ וּבֵ֖ין בַּעֲלֵ֣י שְׁכֶ֑ם וַיִּבְגְּד֥וּ בַעֲלֵי־שְׁכֶ֖ם בַּאֲבִימֶֽלֶךְ׃
And God sent an evil spirit between Abimelech and the men of Shechem; and the men of Shechem dealt treacherously with Abimelech;
Read halakhic rulings (Jewish law) on Judges 9:23: and classical halakhic sources.