This Shabbos, known as Shabbos Hagadol, is the Shabbos before of Pesach, on which it is customary to recite part of the Pesach Haggadah.
Our Sages teach that when the Jews left Egypt, the young children were the first to acknowledge G-d's miracles. To commemorate this, each year it is the Jewish children who introduce the Seder night with their Four Questions, the Ma Nishtana.
Often, children will study these four questions by heart, and recite them at the Seder table. Now, “by heart” doesn’t just mean “from memory,” but that the children ask these four questions “with the heart”—that is, “from deep inside the heart.” Year after year, when children ask the same questions, over and over again, it shouldn’t just be a matter of rote.
For if that were to be the case, the children would already know the answers from the previous year and wouldn’t understand why we are celebrating Pesach all over again this year. Rather, each Pesach should be seen as a new opportunity to discover better answers and reach a deeper understanding of the meaning of Pesach.
And just as children must come prepared with questions, and with a sincere desire to know the answers, parents are expected to tell their children the answers. This is evident in the name of the text that accompanies the Seder tradition—the Haggadah, which comes from the Hebrew vehigadeta levincha, which means “and you shall tell your child.”
Therefore, the days of Nissan leading up to the festival should be seen as an opportunity to double our efforts in preparation for Peasch, not just in cleaning and preparing the home but also in gaining more insight on the festival in preparation to "telling your child."
—from Pearls for the Shabbos Table