Adam Clarke, on Esth 5:14

“Then Zares his wife, and the rest of his friends answered him: Order a great beam to be prepared, fifty cubits high, and in the morning speak to the king, that Mardochai may be hanged upon it, and so thou shalt go full of joy with the king to the banquet. The counsel pleased him, and he commanded a high gibbet to be prepared.”

“Let a gallows be made of fifty cubits high - The word עץ ets, which we translate gallows, signifies simply wood, a tree, or pole; and this was to be seventy-five feet high, that he might suffer the greater ignominy, and be a more public spectacle. I believe impaling is here also meant. See the note, Est 2:23 (note). In former times the Jews were accustomed to burn Haman in effigy; and with him a wooden cross, which they pretended to be in memory of that which he had erected for the suspension of Mordecai; but which was, in fact, to deride the Christian religion. The emperors, Justinian and Theodosius, abolished it by their edicts; and the practice has ceased from that time, though the principle from which it sprang still exists, with the same virulence against Christianity and its glorious Author.”

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