That night the king could not sleep; so he ordered the book of the chronicles, the record of his reign, to be brought in and read to him. It was found recorded there that Mordecai had exposed Bigthana and Teresh, two of the king's officers who guarded the doorway, who had conspired to to assassinate King Xerxes." Esther 6:1-
The king couldn't sleep because he had to remember an intercessor