The 14th of Adar I, is known as "Purim Katan," or the "Small Purim." In a leap year, when there are two months of Adar, the holiday of Purim is celebrated in the second month rather than then first.
The Rebbe explains that Purim Katan is especially relevant to Jewish children, before the age of Bar and Bat Mivtza, as its name indicates. Purim Katan also alludes to the Jewish people, who are referred to as "small." Moreover, Purim Katan also relates to Moshiach, a descendent of King David, about whom it states, "And David was the smallest."
Jewish children, the Jewish people and the Jewish Redeemer are characterized as "small," but they have the power to illuminate the entire world and redeem it. Why? Because they are intrinsically connected to G-d, Who is called the "Great Light."
On Purim Katan 1927, the Previous Rebbe spoke about the special quality of the Torah study of Jewish children, based on the verse "Out of the mouths of babes and sucklings You have founded strength.that You might still the enemy and the avenger." "Babes and sucklings" are Jewish children; "strength" is Torah study; "You have founded strength" refers to the foundation of our lives, the holy Torah; and "the enemy and avenger" is the Evil Inclination. In other words, victory over the enemy is achieved in the merit of the Torah study of the children.
In a conventional war, the biggest and strongest soldiers are chosen to fight. But in the spiritual battle against the Evil Inclination, it is the smallest who lead the way. For true might is not dependent on physical strength, and when young children are given a genuine Torah education, their spirit is the spirit of G-d.
Of course, "the main thing is the deed." Let us all utilize the "Small Purim" to prepare for the "Great Purim," by studying the laws of the holiday and influencing others to observe them. By doing so we will merit the rebuilding of the Holy Temple, speedily in our days.