מדרש אויף אסתר 8:17

“It was during the days of Aḥashverosh…” Rabbi Levi and the Rabbis, Rabbi Levi said: Aḥashverosh is Artaḥshasta. The Rabbis say: [He was called] Aḥashverosh, since anyone who remembers him, his head hurts [ḥoshesh et rosho]. Why did Scripture call him Artaḥshasta? It is because he would anger [martiaḥ] and exhaust [vetash] [others]. Aḥashverosh – Rabbi Yitzḥak and the Rabbis, Rabbi Yitzḥak said: “Aḥashverosh” – as all the troubles came during his days, as it is stated: “there was great mourning among the Jews” (Esther 4:3). “That is Aḥashverosh” – as all the good came during his days, as it is stated: “Joy and gladness for the Jews, a banquet and a holiday” (Esther 8:17). The Rabbis say: “Aḥashverosh” – before Esther came before him; “that is Aḥashverosh” – after Esther came before him, he would no longer copulate with menstruants.

When Israel does His will, the Holy One blessed be He sees any righteous person among the nations and brings him to cling to Israel. So you find Jethro converted through Moses, Rahab through Joshua, and it is written of David "the Gittites, six hundred men" (2 Samuel 15:18). So too you find with Solomon that many converts came through him, as it says "King Solomon numbered all the proselytes" (2 Chronicles 2:16). And so you find in the days of Mordecai and Esther, many converted, as it says "And many from the peoples of the land became Jews" (Esther 8:17).

“The king’s decree about what he will do will be heard throughout his entire kingdom, vast as it is, and all wives will give honor to their husbands, from great to small” (Esther 1:20).
Rabbi Levi and Rabbi Yitzḥak, Rabbi Levi said: We are destined to hear a great decree from that one who will become queen. What is that? “There was great mourning among the Jews” (Esther 4:3). Rabbi Yitzḥak said: We are destined to hear a great decree from that one who will become queen. What is that? “There was joy and gladness for the Jews” (Esther 8:17). Rabbi Yehuda son of Rabbi Simon said: The decree of the King of kings will be heard, who said in His wisdom and His understanding: “I will expunge the memory of Amalek” (Exodus 17:14).
“Vast as it is” – Rav and Shmuel, one said: This kingdom is too vast for this sin; and one said: This sin is too great for this kingdom.¹⁷Rav and Shmuel disagree as to whether the word ‘vast’ in the verse refers to the kingdom, or to Vashti’s sin. “And all the wives will give honor to their husbands…”