In The Queen You Though You Knew, R’ David Fohrman notes how Haman used lots as a form of psychological warfare against the Jews.
R’ Dovid Feinstein emphasizes that Haman wanted the Jews to lose their faith in their ability to reach H-Shem, and therefore not repent. Like Acher in the Talmud (Chagiga 15a), one’s lack of confidence in one’s own relationship with H-Shem can be the greatest impediment to continued spiritual growth.
According to the Maharal, the verse mentions Haman’s terrorizing the Jews as a reference to his threatening our souls, and repeats Haman’s plan to annihilate the Jews as a reference to his threatening our physical bodies.
R’ Bonchek notes that terrorizing the Jews was not merely a convenient effect of the lottery – it was a goal of Haman’s. Not satisfied with murdering the Jews, Haman actually reveled in the psychological torture endured by the Jews once they learned of their impending destruction so many months (11!) in the future.