The Exodus of 15th Nissan took place on a Thursday1 (Gemara Shabbat 87b).
The Shabbat before Pesach is known as Shabbat HaGadol (The Great Shabbat), because of the miracle that was performed on that day (Shulchan Aruch, Orach Chayim 430:1).
What was this great miracle?
Tosfot cites the Midrash2 that states that when the Israelites acquired their Pesach offerings on that Shabbat, the firstborn Egyptians inquired what the Israelites were doing. They replied that it was a Pesach offering for God, who was going to kill the firstborn sons of the Egyptians. Each Egyptian firstborn went to his father and to Pharaoh to request that they let the Israelites go, but they did not agree. So the firstborns waged war [with their fathers] and killed many of them, as it says: Le’Makei Mitzrayim Bivchoreihem (“To He who smote Egypt through their firstborn”)3 – rather than “smote the Egyptian firstborns”. This was a great and important occurrence in the history of our people, and therefore the Shabbat preceding Pesach earned the title Shabbat HaGadol.
Alternatively Rashi, in his halachic compilation Sefer Ha’Orah, suggests that on the day the Israelites acquired sheep and prepared them for slaughter, the Egyptians were enraged to see their deity so helpless and humiliated. Yet, miraculously, they were powerless to interfere or harm the Jews in any way.
Why is it celebrated annually on the Shabbat before Pesach rather than 10th Nissan?
The Levush suggests that the miracle of Shabbat HaGadol began when the Egyptians realised the purpose for which the Israelites were gathering the sheep. Apparently, they knew that sheep were muktzeh, and the Jews must have had some special reason for gathering them on Shabbat. After investigating the matter they discovered that indeed there was a special reason. The Biblical mitzvah of preparing the sheep for slaughter took precedence over the Rabbinic mitzvah of muktzeh. If not for their knowledge of Hilchot Shabbat, they would never have noticed that anything unusual was occurring, and they never would have fought amongst themselves (according to Tosfot) or have been miraculously restrained from harming the Jews (according to Rashi). Since the miracle was due to the halachot of Shabbat, it is commemorated specifically on Shabbat.
In a similar vein, the Prishah writes that the Israelites’ intention to slaughter the sheep was publicised due to the melachah of tying. The Egyptians saw the Jews tying sheep to their beds on Shabbat, and asked them if this was not a desecration of Shabbat. The Jews explained that they were not tying a permanent knot, which is forbidden. They were tying a temporary knot, since they intended to untie the animals soon in order to slaughter them.
Other commentators adopt an entirely different approach. Maharil explains that the Rabbi’s drashah and the piyutim that are added to davening make the Shabbat HaGadol davening similar to the lengthy Yom Kippur service, thus the name Shabbat HaGadol. Alternatively, Maharshal writes that it is called Shabbat HaGadol because the haftorah mentions the “great and awe-inspiring Day of God”.4
1. According to Rabbi Yossi
2. Shemot Rabbah, Parshat Bo
3. Psalms 136:10: “Mitzrayim Bivchoreihem” and not just “Bechorei Mitzrayim”
4. Based on Meorot HaDaf HaYomi, Vol. 322
*Howard, who made Aliyah recently from the UK, set up www.DivreiTorah.co.uk and co-founded chesed organisation www.jGIFT.org. This article is based on insights gained on the Jerusalem-Tel-Aviv train while learning the Daf HaYomi on his way to work!