New Defender's Study Bible Notes
8:3 Haman the Agagite. Agag was a district in Media. Another possibility, however, is that Haman was an Amalekite. The Amalekites, descendants of Esau, had been inveterate enemies of Israel, and Agag was apparently one of their greatest early kings (Numbers 24:7), as well as the name of their last and most cruel king (I Samuel 15:8,33).
8:3 devised against the Jews. Although Haman had been executed, his plan to destroy the Jews had the force of the unchangeable law of the Persians, so Esther pled for an offsetting decree to enable them to survive.