Along with receiving the mitzvah to designate Nisan as the first of the months in preparation for leaving Egypt, as discussed above, the Jewish people also received a series of instructions regarding how to prepare for their imminent exodus from Egypt. Those instructions included taking a sheep or goat on the tenth of Nisan and keeping it until the fourteenth day of the month, when they would slaughter it. The blood was then placed on the side and top door posts of their homes, and the meat was roasted to be eaten along with unleavened bread, matzah and bitter herbs, maror. At midnight, God passed over their houses and struck the first born of Egypt, the final plague which caused Pharaoh to finally relent and let the Israelites go free.
The tenth of Nisan that year was a Shabbat. Today, although the tenth of Nisan does not necessarily come out on a Shabbat, we still call the Shabbat right before Pesach Shabbat Hagadol, The Great Shabbat, in remembrance of that special Shabbat before we left Egypt. Other commentators point out two other reasons for calling this auspicious Shabbos Shabbat Hagadol. Over the generations it became customary for rabbis to give well attended public talks on the Shabbat before Pesach, which would include important points of Jewish law in preparation for the approaching holiday, as well as deep insights to spiritually inspire the congregation leading up to Seder night. Thus, this Shabbat was called Shabbat Hagadol, due to the importance of these special presentations or drashot.
Another reason suggested for the use of the name Shabbat Hagadol is connected to the end of the accompanying haftorah, when the prophet Malachi prophesizes: “Behold, I send you Elijah the prophet before the great (gadol) and awesome day of God” (3:23). Nisan in general, and Pesach specifically, is a time of great anticipation of the coming of Mashiach and redemption. According to tradition, Elijah the prophet will return to herald the Mashiach’s arrival. Thus, the haftorah reflects that expectation. Since the prophet calls the coming days of redemption “great,” this Shabbat is called Shabbat Hagadol, the “Great Shabbat.”
It is interesting to note that in the Hebrew calendar the tenth of Nisan is exactly 180 degrees opposite the tenth day of the month of Tishrei, the day of Yom Kippur. What these two dates have in common is the concept of mesirut nefesh, which means to give your whole being, to go beyond what you think you are capable of. Taking a sheep on the tenth of Nisan was an act of mesirut nefesh, as sheep were considered one of the gods of Egypt. When the Egyptians demanded to know why they were taking sheep into their houses the Israelites answered honestly: in four days, we are going to slaughter these sheep and then leave Egypt. God purposely put them in that position of rebellious vulnerability, for after years of oppression and slavery it would take nothing less than a total paradigm shift to ready the people for freedom. In such a situation, nothing less than mesirut nefesh could facilitate such a drastic shift of status and consciousness. Yom Kippur as well has a strong element of mesirut nefesh, as fasting for a full day, along with the long prayers and intense internal spiritual work needed to achieve atonement stretches the physical and mental energies of most people to the limit. Yet, like the tenth of Nisan in Egypt, nothing less than one giving their all can achieve the type of spiritual elevation and purification that is available on Yom Kippur for those willing to stretch themselves beyond their usual physical and spiritual capabilities.