John Gill Commentary Judges 9:57

"and all the wickedness of the men of Shechem did God requite upon their heads: and upon them came the curse of Jotham the son of Jerubbaal." — Judges 9:57 (ASV)

And all the evil of the men of Shechem
In aiding Abimelech to slay his brethren, and in making him king after so foul a fact committed:

did God render upon their heads ;
by suffering Abimelech to beat down their city, and destroy the inhabitants of it, and by burning the hold in which the men of the tower of Shechem were, and them in it:

and upon them came the curse of Jotham the son of Jerubbaal ;
both upon Abimelech, and the men of Shechem, they being destroyed by one another, as Jotham imprecated they might, and foretold they would, see (Judges 9:20) .