The Shabbat before Pesach is given the special name "Shabbat Ha’gadol" – "The Great Shabbat."

Various explanations have been given for this name, the most famous of which is that suggested by the Tur. It was on the Shabbat before the Exodus, the Tur writes, that Beneh Yisrael were required to take a sheep and prepare it for the Pesach sacrifice which they would offer four days later, on the afternoon before the plague of the firstborn. The Egyptians, who worshipped cattle, saw Beneh Yisrael walking about with sheep and asked what they were doing. Beneh Yisrael fearlessly explained that they were preparing the sheep to be slaughtered as a sacrifice to Hashem. Despite this affront to their pagan beliefs, the Egyptians were unable to cause any harm to Beneh Yisrael. This great miracle, which occurred on the Shabbat before the first Pesach, is celebrated on Shabbat Ha’gadol, which is so named because of the great miracle which transpired on this day.

The question, however, remains as to why this miracle is celebrated on the Shabbat before Pesach, and not on the calendar date on which it occurred – the 10th of Nissan. Why was specifically Shabbat chosen as the time for celebrating this great miracle?

Rav Pinchas Friedman (contemporary) explains the particular relevance of Shabbat to the miracle that happened on the 10th of Nissan before the Exodus. The Gemara teaches that it is forbidden for a non-Jew to celebrate Shabbat; meaning, not only are gentiles not obligated to observe Shabbat – they are prohibited from doing so. The Hid"a (Rav Haim Yosef David Azulai, 1724-1806), in his work Rosh David, explains this prohibition based on the fact that Shabbat is similar to "Sharbito Shel Melech" – a king’s scepter. Using a king’s scepter is a capital offense, as it constitutes a grave infraction on the king’s honor. However, a king would certainly allow his beloved child use his scepter. The Jewish People are G-d’s beloved children, as Moshe Rabbenu tells us in the Book of Debarim: "You are children of Hashem your G-d." Therefore, we are allowed to observe Shabbat – G-d’s "scepter" – while other nations may not.

Rav Friedman proceeds to cite the comment of the work Noam Megadim explaining that Beneh Yisrael earn this stature of G-d’s children when we reject all other deities besides the one, true G-d. Whereas other nations believe in G-d as well as other deities, we profess our belief in only G-d Himself. Rav Friedman thus explained that it was specifically on Shabbat that Beneh Yisrael needed to prepare their sheep for the Pesach offering – because in so doing, they proclaimed their firm rejection of the Egyptians’ pagan beliefs. Our Sages teach us that during the period of exile in Egypt, Beneh Yisrael – while still believing in G-d – practiced the idol-worship of the Egyptians. Over the course of their stay in Egypt, living with constant exposure to the Egyptians’ belief system, they gradually adopted the Egyptians’ beliefs and practices. However, on the 10th of Nissan, on the Shabbat before the Exodus, Beneh Yisrael resoundingly rejected the Egyptians’ idol-worship. On that Shabbat when they prepared a sheep for the sacrifice, they proclaimed publicly and loudly that they worshipped only the one, true G-d. And so at that moment, they truly became G-d’s children – and therefore this took place specifically on Shabbat, the day which underscores our nation’s unique status as Hashem’s beloved children.

This is the reason why we celebrate this miracle specifically on Shabbat – because the event of Beneh Yisrael’s designation of a sheep for the Pesach sacrifice marked their becoming G-d’s children, a special stature which underlies our observance of Shabbat. Shabbat Ha’gadol thus celebrates our status of G-d’s beloved children, an exalted status which we earn through our firm affirmation that we do not place our trust in anyone or anything other than the single Creator of the universe.