Bible Notes Online - Esther 4 - ESV
Commentary

v1-3: There was great sorrow amongst the Jews.

Mordecai did not break the command about approaching the palace in sackcloth; however, he did refuse to bow before Haman. Thus, a distinction is made between breaking God's command, bowing before a man, and issues of culture.

v4-5: Like Rachel weeping for her children, Mordecai refused to be comforted. Apparently, Esther, within the palace, had not heard about the king's decree.

v6-8: Mordecai sent back the message to Esther, explaining the decree. He also asked that she approach the king, to intercede for her people.

v9-11: The absolute power of the monarch, before whom no man or woman had any rights.

The fact that Esther had been kept out of the King's presence for thirty days indicates his unpredictability. This was mixed with his ultimate power over a huge empire and its inhabitants.

Since the time of the Assyrian empire, a single man had had great power over large areas of the Middle East. Whilst the Assyrians and Babylonians had been cruel, the Medes and Persians, although less cruel, still maintained a great power, see Dan 6.15.

v12-14: Mordecai's response; Esther would not be spared destruction. He was confident that "relief and deliverance" would arise for the Jewish people. Yet Esther had been raised up for just this situation. Relief and deliverance was guaranteed because God had made promises to Abraham (Gen 12.1-3) concerning the nation of Israel.  Mordecai knew these promises.

v15-17: Esther's sacrifice, taking the risk of going into the king. She had not been allowed in his presence for a month, yet she risked her own life, "I will go to the king". She could give nothing more than her life. Her life was like a drink offering, Phil 2.7; 2 Tim 4.6.

The sadness is that no one could have confidence in the king's mercy. Our confidence is that the God and Father of our Lord Jesus Christ is full of mercy.

Notice that there was clearly an identifiable community of Jews in Susa who would stand together. Indeed, had Haman's scheme been successful, they would have died together.