This Shabbat, the one preceding Pesach, is known as Shabbat HaGadol. There are a variety of opinions regarding how this Shabbat received its name. The Shulchan Aruch (530:1) states rather ambiguously that this name was received because of the miracle which occurred on this Shabbat. The Mishnah Berurah (530:1) explains that the tenth day of Nissan was a Shabbat in the year in which the Jews lefts Mitzrayim. On that Shabbat, the Jewish people took sheep, animals which were considered gods by the Egyptians, and tied them to their bed posts. When the Egyptians saw this and were furious, the Jews explained that they were fulfilling Hashem’s commandment by slaughtering the sheep for the Pesach sacrifice. Since the Egyptians experienced this utter denigration of their god and did not harm the Jews, it was considered to be a great miracle, and thus, this Shabbat was called Shabbat HaGadol, The Great Shabbat.
Rav Moshe Feinstein offers a different explanation as to how this Shabbat received its name. He explains that Shabbat represents that Hashem created the world in six days and rested from creation on the seventh day. Pesach is a continuation of this theme in that it represents Hashem’s continued presence and control over this world. Not only did Hashem create the world, but he still plays an active role in this world. When Par’oh saw the plagues that Hashem casted upon Egypt, he understood that Hashem was the true ruler of the universe. We see how great (Gadol) Shabbat is for our belief in Hashem. That is the reason why Shabbat is listed amongst the holidays of the (VaYikra 23:3). Without Shabbat, believing the concept of the holidays, that Hashem runs the world, is deficient. Therefore, the Shabbat before Pesach, which connects Shabbat and Pesach, is called Shabbat HaGadol, since we learn this great message that Hashem both created the world and continues to run the world.
The Gemara (Rosh HaShanah 10b) states, “In Nissan we were redeemed, and in Nissan the future redemption will come.” It is by recognizing and understanding the theme of Pesach, by realizing that Hashem is our King, Creator and Ruler, that we can merit the redemption. Let this year be the Nisan in which Mashi’ach comes, and let us be alive to witness the greatest manifestation of Hashem’s rule of the earth by bringing our final redemption.