Esther 2:21

He sat at the king's gate. By the custom of that part of the world, this was a public gathering place. People met there to hear news and to talk with friends and others. Some say Mordecai sat in the king's gate because he held a government office. That idea must be rejected as wrong.

Any citizen, it seems, could sit there, and Mordecai used that freedom to stay as near to Esther as he could. Esther had still not told anyone her nationality, obeying what Mordecai had told her. … These circumstances too are part of God's working behind the scenes.

According to Jewish tradition they meant to put a poisonous reptile in the king's cup just as he was about to drink. Mordecai overheard the plot and at once told Esther, and she told the king about it in Mordecai's name. … (King Ahasuerus, Xerxes, died by assassination in 465 B.C. Artaban, the commander of his cavalry, plotted with Mithridates, the king's trusted personal attendant. Mithridates let him into the king's bedroom, and Artaban stabbed him to death while he slept.)

Suppose Esther had revealed her connection to him. Suppose people had learned that Mordecai at the gate was her uncle, and she his adopted daughter. Then he would not have stayed in that unnoticed place before the gate. The plotters would have been careful. They would not have spoken where a close relative of the queen could hear them. Mordecai learned of the plan to kill the king only because nobody knew who he was, and so nobody paid him any attention.

In his dealings with the royal court, he watches out for the king's welfare in the open, sitting at his gate, so as to keep any danger away from him. Esther's future depended on Ahasuerus staying alive, so Mordecai becomes the king's rescuer. Then he withdrew in silence, asking nothing for himself, and let Providence direct him — Providence was all his oppressed nation had left. It was Providence which had led those two officers of the court to speak of their plans in front of Mordecai. Providence had prepared Esther's ear to receive the news. Providence had arranged that these matters be written into the book of the chronicles in the king's own presence.

The traitors were found guilty. But the man who had saved the king was forgotten, oddly enough, until the hour of real need came. That delay only made his reward more certain, and made it come at last to the dismay of the enemy. Hidden providence ordered everything well, however hard things looked. Here again, as with the plotters and Mordecai, the warning that reached the king was no more accidental than the fall of Vashti or the rise of Esther. All was in the hand of Him who ruled unseen.

Strange as it sounds, the Jew becomes important to the ruling power — that is, to the Persian. And more than I have said so far: important to his safety as well as to his pleasures. For Mordecai becomes his protector, as Esther had become his wife. This we see at the close of Esther 2. The king is in debt to both. Despite all his greatness, and all the means of happiness and strength that came with it, he is in debt to the scattered people of Judah.