A wrongful action can cause a bad reaction many years later. On the other hand, a good action can serve as a tikkun (correction) for a wrongful act.

Let's first analyze how a wrongful act can lead to a bad reaction in the future: Yitzchak was sure that Esav, their firstborn, was to be the spiritual heir. Rivka, however, believed that Yaakov was to be the spiritual heir since Esav did not have the proper character traits to be the spiritual leader of the Jewish people.

The liturgical poet, Eliezer HaKalir, draws on the midrash and aggada to describe Esav's bad character traits in a poem that many congregations read on Shabbat Zachor:

Zachor, Remember Esav who caused Avraham to die five years before his time with murder, trickery and adultery, Esav frightened him.

Zachor, Remember the one whose way was the reverse of an honest man, who was a stranger to truth, who blinded his father with incense and idolatry, he planned inwardly to be cruel to his brother.

Rivka may have seen through ruach hakodesh, the divine spirit, that Yaakov would be the proper spiritual heir. However, the way that Rivka put into effect a scheme that would trick Yitzchak into blessing Yaakov thinking that he was really Esav may be looked at as a mistake in judgement that caused Yaakov to suffer greatly later on. It may have even caused Yaakov's descendents, the Jewish people, to suffer until this very day.

Eliezer HaKalir's poem continues:

Zachor, Remember Esav from whom blossomed Amalek.

Amalek was a descendent of Esav. Is it a coincidence that throughout the centuries the Jewish people, descendents of Yaakov have suffered at the hands of Amalek, the descendents of Esav?

When Esav heard that Yaakov took his blessing, he cried out "Vayitzak tzeaka gedolah u'marah", an exceedingly bitter cry (Breisheet 27:34).

Is it a coincidence that years later in Megillat Ester, when Mordechai, a descendent of Yaakov, hears that Haman, a descendent of Esav is about to destroy the Jewish people he lets out a similar cry "Vayizak zeaka gedolah u'marah" (Ester 4:1)?

According to Yalkut Shimoni, Mordechai cried out and said, my ancestor Yitzchak, what have you done to me? Esav cried out and you listened to his cries and blessed him. Now we are about to be sold and slaughtered by Haman, a descendent of Esav.

Yaakov caused Esav to cry and in the end Haman caused Mordechai to cry.

Let's now analyze how a good action can serve as a tikkun (correction) in the future.

Consider the story in this week's Haftara. King Saul fought Amalek. However, he did not fight properly, he took from the spoils and was therefore punished. In Megillat Ester, Mordechai, a descendent of Saul is also fighting Amalek (Haman). Mordechai does not get punished for Saul's mistake, rather he fixes it. Whereas Saul took from the spoils of Amalek and is stripped of the kingdom, Mordechai is described as not touching the spoils on three occasions and therefore he retains the title as second to the king.

Another fixing is that while Saul failed to kill Agag, a descendent of Amalek, Mordechai arranges for Haman, a descendent of Agag to be killed.

Everything that we do has impact. Every action has a reaction. A word or an action can make a whole world of difference. You never know. You just never know.