Tomorrow, Thursday, we will observe Ta'anis Esther [the fast of Esther]. On most years it is the day before Purim, that is the 13th of Adar. This year, however, Purim falls on a Sunday. Consequently, the fast is pushed up to Thursday, as is the case with most fasts that would fall out on the Sabbath. On most years, the fast is extended beyond the usual time of nightfall, as we hear the entire Megillah before eating. This year, like the inhabitants of Jerusalem, who celebrate the holiday every year on the 15th of Adar, there is a break between the fast day and the holiday, so there is no delay in breaking the fast.
The fast is named for the heroine of Megillas Esther,who declared a three day fast prior to her approaching the king. As the law held anyone who approached the king without a royal summons punishable by death, there was very real danger in coming. She could have tried to wait until the king would be in the mood to see her. But Mordechai told her that in this case she did not have the right to remain silent but had to take action to save her people. He assured her that if she would not be the agent of their salvation, G-d would find another. Esther then resolved to do what she had to even at risk of her own life.
But she didn't just take the plunge without a plan. The first step was the spiritual preparation inherent in the fast. Then she invited the king and Haman -- the one behind the plan to annihilate the Jews --to a feast. At the feast, the king offered her whatever her heart desired, but all she requested was that the king and Haman attend a second feast. This aroused both the curiosity and jealousy of the king. So when she finally revealed that someone was seeking the destruction of herself and people, the king was in an emotional state to side with the queen rather than his favorite minister. Haman was hung on the very gallows he had set up for Mordechai, and the Jews were granted permission to defend themselves and kill their enemies. That is the miracle that is celebrated on Purim with the yearly recounting of the story, feasting, mishloach manos, and gifts to the poor.
Despite the proximity of the two occasions, the feasting and revelry on Purim is not like that of Mardi Gras. It is the celebration of Jewish survival which was achieved through unity. The Jews came together in fasting, fighting, and then in feasting. The fast today commemorates the 3 days fast, as well, as the day spent in battle with our enemies. The feast day of Purim is set for the day the Jews saw that they had prevailed and to express their thanks for having come through together.
Readers with an advanced level of Jewish knowledge may also be interested in: http://kallahmagazine.blogspot.com/2010/02/poetic-justice-as-sign-of-div...