Midrash su Ester 2:21

(Est. 2, 21) In those days, while Mordccai was sitting in the king's gate, Bigthan and Theresh became wroth. R. Acha b. Abba, in the name of R. Jochanan, said: "The Holy One, praised be He! causes masters to be wroth against their servants, in order to do the will of the just, and He also causes the wrath of slaves against their masters, in order to do the will of the just." The wrath of the masters against their servants, as it is written (Gen. 41, 10) Pharaoh was wroth with his servant; to do the will of the just, as it is written. And there was with us a Hebrew lad, etc. And he makes slaves wroth against their masters, as it is written (Ext. 2, 21) In those days Bigthan and Theresh became wroth. To do the will of the just. This refers to Mordecai, as it is written, And the thing became known to Mordecai. R. Jochanan said Bigthan and Theresh were Tarsians, and spoke their own language. They spoke between themselves: Since Esther has come into the court, our eyes have not seen any sleep; let us put poison into the king's drink, in order that he should die." And they knew not that Mordecai was a member of the Great Sanhedrin, every one of whom knew seventy languages. Then Bigthan said to Theresh: "But my hour of duty is not the same as yours." "I will watch for you, too," answered Theresh. Then we understand the passage, And the thing was inquired into, and found true, to mean that he had not been at his post.

“In those days, Mordekhai was sitting at the king's gate; two of the king's officials, Bigtan and Teresh, among the doorkeepers, became angry and sought to lay hands on King Aḥashverosh” (Esther 2:21).
“In those days, Mordekhai was sitting at the king's gate; two of the king's officials, Bigtan and Teresh […became angry]” – what was the anger there? He relieved two and set one in their place; he relieved two aristocrats who were the doorkeepers and set that barbarian [in their place].¹⁸They took Mordekhai to be a barbarian.
“Was sitting at the king's gate” – Rabbi Berekhya said in the name of Rabbi Levi: It is written: “Come behold the works of the Lord, who made desolations on the earth” (Psalms 46:9). He incited servants against their master, to bestow greatness upon the righteous; that is what is written: “Bigtan and Teresh became angry…” – to bestow greatness upon Mordekhai. He incited masters against their servants to bestow greatness upon Joseph; that is what is written: “Pharaoh became angry with his servants” (Genesis 41:10).

“Who is she who appears like dawn, fair like the moon, pure like the sun, formidable like banners?” (Song of Songs 6:10)
“Who is she who appears like dawn?” There was an incident in which Rabbi Ḥiyya and Rabbi Shimon ben Ḥalafta were walking in the Arbel Valley in the early morning and they saw the light of dawn breaking. Rabbi Ḥiyya the Great said to Rabbi Shimon bar Ḥalafta: So will the redemption of Israel burst forth, as it is written: “Though I sit in darkness, the Lord is a light for me” (Micah 7:8). Initially it will come little by little, then it will sparkle, then it will increase, and then it will continuously spread. So too, initially, “In those days, Mordekhai was sitting at the king’s gate” (Esther 2:21), then, “Mordekhai emerged from before the king in royal garments” (Esther 8:15), and then: “For the Jews there was light and joy…” (Esther 8:16).
“Like dawn,” if so, just as the dawn has no shade, could it be, perhaps, that the same is true of Israel?³⁴Is it true that they have no protection? The verse states: “Fair like the moon.” If so, just as the light of the moon is not clear, perhaps the same is true of Israel? The verse states: “Pure like the sun,” that is what is written: “Let those who love Him be like the powerfully rising sun” (Judges 5:31). If so, just as the sun beats down, is the same, perhaps, true of Israel? The verse states: “Fair like the moon,” that is what is written: “How precious is Your kindness, God” (Psalms 36:8). If so, just as the moon is at times deficient and at times full, is the same, perhaps, true of Israel? The verse states: “Pure like the sun.” If so, just as the sun serves by day and does not serve by night, is the same, perhaps, true of Israel? The verse states: “Fair like the moon,” just as the moon serves by day and by night, as it is written in its regard: “To rule by day and by night” (Genesis 1:18), so too Israel, they are in this world and they are in the World to Come. If so, just as the sun and the moon do not induce fear, is the same, perhaps, true of Israel? The verse states: “Formidable like banners,” like the banners On High, like Mikhael and his banner, Gavriel and his banner. From where is it derived that they induce fear? As it is stated: “They had backs, and they were tall, and they were fearsome” (Ezekiel 1:18).
Rabbi Yehoshua said: It is like the fear of those below, e.g., dukes, governors, and generals. From where is it derived that they induce fear? It is as it is stated: “Fearsome, terrifying, and strong” (Daniel 7:7). Rabbi Yudan and Rabbi Huna, Rabbi Yudan in the name of Rabbi Eliezer son of Rabbi Yosei HaGelili and Rabbi Huna in the name of Rabbi Elazar HaModa’i: “Like banners [kidgalim],” is not written here, but rather kanidgalot,³⁵ Degalim, in the masculine, would be perceived as an allusion to angels or leaders. Nidgalot, in the feminine, is an allusion to the exile [galut]. like the generation that was sliding toward exile. Which is this? This is the generation of Hezekiah, as it is stated: “A day of distress and rebuke” (Isaiah 37:3). From where is it derived that they induced fear? It is as it is stated: “He was thereafter exalted in the eyes of all the nations” (II Chronicles 32:23).
Rabbi Huna [said] in the name of Rabbi Elazar HaModa’i: “Like banners [kidgalim]” is not written here, but rather kanidgalot, like the generation that would slide toward exile, but would not be exiled. Which is this? This is the generation of the messianic king. That is what is written: “I will gather all the nations to Jerusalem for the war” (Zechariah 14:2). From where is it derived that [the messianic king] will induce fear? As it is stated: “He will strike the world with the rod of his mouth” (Isaiah 11:4). Rabbi Elazar in the name of Rabbi Yosei bar Yirmeya: At that time, Israel will be moving from journey to journey.
Rabbi Yehoshua of Sikhnin says: The congregation of Israel said: ‘The Holy One blessed be He brought me to a wine cellar, this is Sinai; Mikhael and his banner and Gavriel and his banner were there.’ It said: ‘If only we could travel like the supernal array.’ At that time, the Holy One blessed be He said: ‘Since My children desire to be like the banners, they shall encamp by banners,’ as it is stated: “Each at his banner with the insignias by their patrilineal houses, the children of Israel shall encamp” (Numbers 2:2).