On a fast day we convert the “inui,” suffering, into a “desirable day.” The Fast of Esther is not connected to the destruction of the Beis HaMikdash. When Mashiach comes we will still fast on the Fast of Esther. The “reaffirmation of the faith” is the theme of Purim; it derives from the preparation of Taanis Esther, and goes beyond the scope of intellect. A leap year teaches that we can compensate for the past and provide for the future. In Torah and mitzvos there must be zealousness. In the leap year we see more clearly how the liberation of Purim is brought close to the liberation of Pesach.