After Esther was chosen queen of Persia she asked the King why he had not chosen for himself a Jewish adviser, as other Kings had done. She reminded him that even the mighty Nebuchadnezzar had a Jewish adviser, the prophet Daniel. The King replied that he did not know of any Jew who was worthy of being his adviser.

"There is Mordechai," said Esther, "wise, pious and loyal."

Mordechai thus became adviser to the King.

One day, Mordechai overheard in the court a conversation between two of the King's attendants, Bigtan and Teresh. He learned that they planned to poison the King because he had deposed them from their rank as chief chamberlains and subordinated them to Mordechai. They wanted everybody to believe that so long as they took care of the King, he was safe, but as soon as a Jew was appointed the King was poisoned!

Although they were Tartians and spoke in their native tongue, Mordechai, who was a member of the Sanhedrin and therefore required to understand all languages, had no difficulty in understanding their conversation. He told Esther of the wicked plot. Esther, in turn, informed the King of it in Mordechai's name. When the King requested his usual drink after his afternoon rest, the unsuspecting attendants, Bigtan and Teresh, brought him his drink containing the poison they has put in it. The poison was immediately discovered in the cup, and the two were condemned to die. Thereupon it was recorded in the Royal Book of Chronicles that Mordechai had saved the King's life.