Haman offered King Ahashverosh a considerable sum for permission to kill all the Jews in his kingdom, but the king acquiesced immediately and without payment. The Sages portray this agreement with a parable about a person who was very glad for the opportunity to be rid of an item that he did not need.

“The king said to Haman: The silver is given to you, and the people, to do with them as it is pleasing in your eyes” (Esther 3:11). Rabbi Abba said: The actions of Ahashverosh and Haman can be understood by means of a parable; to what is the matter comparable? It is comparable to two individuals, one who had a mound in the middle of his field and the other had a ditch in the middle of his field. The owner of the ditch said: Who will give me for money this mound with which to fill my ditch? The owner of the mound said: Who will give me for money this ditch into which I can move my mound? One day, they met one another. The owner of the ditch said to the owner of the mound: Sell me your mound. He said to him: Take it for free; would that it would be so. (Megilla 13b)