The king agreed without any investigation. He appears irresponsible and easily influenced. By removing his signet ring, the king gave up control over official policies. By giving it to Haman, he showed that Haman had full authority to seal the decree.
the enemy of the Jews: The narrator's new title for Haman hints at his power to harm the Jews (see also Esther 8:1; 9:10, 24).
Keep your money...These people are given to you to do: It seems the king did not want the bribe, but Genesis 4:7 suggests Haman did give the money. The king followed a common practice to make the bribe and his greed less obvious (compare Genesis 23:10–16). For public appearance, the king pretended not to care about the money, but he actually did.