Shabbat Parashat Zachor-The Sabbath of Remembering

Shabbat Parashat Zachor – The Sabbath of Remembering is named for the special Torah reading that is added to the Shabbat morning Torah service. Zachor is always the Shabbat before Purim.

In addition to the regular weekly Torah reading, Deuteronomy 25:17-19 is read which commands the Jewish people to remember that the nation of Amalek attacked the elderly and weak of the Jewish people three days after the Jews crossed the Red(Reed) Sea. Amalek is a wicked people whose memory must be erased from the world.

Parashat Zachor is read on the Shabbat before Purim because Haman was the direct descendent of Agag the Amalekite king who was defeated, but temporarily spared, by King Saul (as recorded in Samuel I 15).

While women are not obligated to hear Parashat Zachor, because they are not obligated in the commandments of war, it has become obligatory since Jewish women have taken it upon themselves to hear the parasha.

For a more in-depth discussion of this see:
Hanging Haman: The Commandment to Wipe Out Amalek