Midrash Esther I-Achashveirosh-Bitter Drink
“Now it came to pass in the days about how Achasveirosh.” Rabbi Joshua son of Karcha said: he was called Achashveirosh because he made the face of Israel black like the sides of a pot.
Rabbi Berechiah said: because he made the head of Israel ache with fasting and affliction.
Rabbi Levi said: because he made them drink gall and wormwood.
Rabbi Judah said: because he sought to uproot Israel from the foundation of their future.
Rabbi Tachalifa the son of bar Chana said: because he was the brother of the head, the brother of Nebuchadnezar. How could he be his brother? Was not one a Chaldean and the other a Median? The fact is that one stopped the building of the Temple and the other destroyed the Temple; therefore Scripture puts them on the same level. (Esther Rabbah 1:1)
Rabbi Levi describes Achashveirosh as causing people to drink bitter liquids, gall and wormwood. Rabbi Levi is not focusing on the fast, a single event in the Book of Esther, but rather the fact that all that Achashveirosh did left a bitter taste in the mouths of his subjects. He wants us to read the entire story not only from the perspective of the King, but to reflect on how the king’s subjects experienced the actions of this wicked King.