תוספות ד"ה ואותו יום חמישי בשבת היה כו' - ואם כן ברביעי שחטו פסחיהם ונמצא בשבת שעברה לקחו פסחיהן שאז היה בעשור לחדש ועל כן קורין אותו שבת הגדול לפי שנעשה בו נס גדול כדאמרינן במדרש (שמות רב פ' בא) כשלקחו פסחיהם באותה שבת נתקבצו בכורות אומות העולם אצל ישראל ושאלום למה היו עושין כך אמרו להן זבח פסח לה' שיהרוג בכורי מצרים הלכו אצל אבותיהם ואל פרעה לבקש ממנו שישלחו ישראל ולא רצו ועשו בכורות מלחמה והרגו מהן הרבה הה"ד למכה מצרים בבכוריהם:
And that day [of Pesach in Egypt] was Thursday etc. - If so, they slaughtered their Pesach offerings on Wednesday, and it emerges that the previous Shabbos they acquired their offerings, for that was the tenth day of the month. And therefor it is called Shabbos HaGadol, for there occurred upon it a great miracle, as the Midrash states, that when they acquired their Pesach offerings on that Shabbos, the firstborn sons of the nations of the world came to the Jews and asked them what they were doing. [The Jews] respondend to them that this is a Pesach offering for Hashem who will kill the firstborn sons of the Egyptians. [The Egyptian firstborn sons] then went to their father and to Pharoh to request that he let the Jews go, but they did not agree. So the firstborn sons waged war [with their fathers] and killed many of them, as it says: To he who smote Egypt through their firstborn sons.1
Many later authorities ask why this specific miracle is celebrated annually on the Shabbos before Pesach, and not on the tenth of the month of Nisan.
Bach2 answers that the tenth of Nisan is the anniversary of two other major events: The death of Miriam in the last year before the Jews entered the Land of Israel, and the crossing of the Jordan river as the Jews finally entered the Land of Israel. We therefore do not celebrate the miracle on the tenth day of the month, as doing so would remind us of Miriam’s death, and diminish our happiness on the one hand, and on the other hand doing so would diminish the emphasis placed on celebrating the Exodus, as it would remind us of our crossing of the Jordan.3
Perishah4 suggests that Shabbos was the catalyst of the events that followed, in that the Egyptians knew that the Jews kept Shabbos, and therefore asked why they were acquiring the sheep, and especially wanted to know how the Jews could desecrate the Sabbath by tying the sheep and goats so that they would not run away. The Jews responded that this was a unique commandment from Hashem. This was how the Egyptian first born sons became aware of the problem, from which time the miraculous events began to unfold.
Taz5 cites R’ Moshe Charif as having given the answer that the tenth of the month commemorates the crossing of the Jordan as well, and that therefore a celebration the miracle of the acquisition of the offerings on the tenth might be diluted by the memory of the miracle of the crossing. Taz stlates that he related this answer to his father-in-law (Bach) who praised the answer.
R’ Yaakov Kamenetsky6 notes that Bach, in turn, states cocerning this answer, that he “received” it.7 Reb Yaakov takes it for granted that Bach “received” this answer from his son-in-law, Taz. He therefore concluded that when authorities describe some statement as a “Kabbalah,” it does not necesarily mean that they received the idea they are stating as a tradition from earlier generations, but rather that they heard the idea and accepted it because it found favor in their eyes!
Because of the significance of the appelation gadol - great, Chida8 writes that although it is said in the name of Arizal that the proper form of blessing another person on Shabbos is Shabbos Shalom UMevorach, on this special Shabbos the custom is to say: Shabbos HaGadol UMevorach.
תהלים פרק קל"ו פס' י'.
או"ח סי' ת"ל.
עיין ערוך השלחן, או"ח סי' ת"ל סעיף ב'.
או"ח סי' ת"ל ס"ק א'.
אמת ליעקב לאו"ח סי' ת"ל סעיף א'.
"ואני קבלתי דהטעם הוא וכו'", עיי"ש.
בס' מחזיק ברכה, הובא בס' מנהג ישראל תורה, או"ח סי' ת"ל ס"ק א'.