Esther 2:21-23

21One day as Mordecai was on duty at the king’s gate, two of the king’s eunuchs, Bigthana and Teresh—who were guards at the door of the king’s private quarters—became angry at King Xerxes and plotted to assassinate him.

22But Mordecai heard about the plot and gave the information to Queen Esther. She then told the king about it and gave Mordecai credit for the report.

23When an investigation was made and Mordecai’s story was found to be true, the two men were impaled on a sharpened pole. This was all recorded in The Book of the History of King Xerxes’ Reign.