Keil & Delitzsch, on Esth 9:25

“And afterwards Esther went in to the king, beseeching him that his endeavours might be made void by the king’s letters: and the evil that he had intended against the Jews, might return upon his own head. And so both he and his sons were hanged upon gibbets.”

“וּבבאהּ, and when it (the matter), not when she, Esther, came before the king, - for Esther is not named in the context, - he commanded by letters (Est 8:8), i.e., he gave the written order: let the wicked device which he devised against the Jews return upon his own head; and they hanged him and his sons upon the tree.”

Imported from an open dataset — not yet checked against the printed edition.