The tzaddik prepared within galus

במגלת אסתר איש יהודי הי' כו' במדרש מוכן לגאולה.

In Megillas Esther it says "There was a certain Jewish man," etc.; the Midrash explains that he was prepared for the geulah (redemption).

The Midrash reads the verse introducing Mordechai as hinting that he was specially "prepared" — set in place by Hashem as the instrument of redemption.

דחז"ל דרשו הגלה מעצמו.

For Chazal expounded that he exiled himself of his own accord.

Chazal note that Mordechai went into galus (exile) willingly, not by force — a deliberate choice that made him fit to become the seed of the redemption.

להודיע כי בכל גלות הקב"ה וב"ש מכין צדיק אשר הוא אינו בגלות ונכנס בין הגולים כדי להיות הכנה לגאולה ולכן כתיב ומרדכי לא יכרע שהי' מוכן שהוא לא יכרע.

This teaches that in every galus, Hashem (blessed is He) prepares a tzaddik who is not truly in exile, and who enters among the exiles in order to be the preparation for the geulah; therefore it is written "And Mordechai would not bow," for he was prepared from the outset that he would not bow.

In every exile Hashem plants a tzaddik whose inner self remains free even amid the galus. Mordechai's refusal to bow was not mere defiance but the expression of an inner freedom already prepared within him — the spark from which redemption grows.

ולכן לא יכול המן ימ"ש לשלוח יד בו לבדו רק בכל היהודים שהיו אז במצב השפל.

Therefore Haman (may his name be blotted out) could not lay a hand on him alone, but only against all the Jews, who were then in a lowly state.

Because Mordechai himself stood untouched in his inner freedom, Haman had no grip on him as an individual; his power could only reach the nation as a whole, which had sunk into a degraded spiritual condition.

וכשהתחיל לחשוב על מרדכי בלבד והכין העץ היה זה הכנה למפלה שלו:

And when he began to plot against Mordechai alone and prepared the gallows, this itself became the preparation for his own downfall.

The very moment Haman turned his designs upon the untouchable tzaddik and built the gallows, he was unknowingly preparing the instrument of his own ruin — for one cannot harm the inner point that Hashem has set aside for redemption.

Summary: In every galus Hashem prepares a tzaddik whose inner self stays free of the exile; Mordechai was such a one, and his unbowed inner freedom both shielded him from Haman and turned Haman's own scheming into the seed of his downfall.