Nissan is known as the “Month of Redemption.”1 This is because the central theme of the month is the holiday of Pesach, the “Time of our Redemption.”2 This theme receives special emphasis on the Shabbos that precedes Pesach, known as Shabbos HaGadol , “The Great Shabbos.”

The word Nissan is related to the word nes , or miracle.3 Moreover, Nissan possessing as it does two letters nun, is indicative of “miracle of miracles”4 — the spectacular miracles that G‑d performed during this month in taking the Jews out of Egypt.

This is particularly emphasized on Shabbos HaGadol , “for on this Shabbos there occurred a great miracle,”5 referring to the extraordinary miracle smiting of the Egyptians through its first-born. Moreover, “on this day the redemption and miracles [of the exodus] began.”6

Why is “smiting the Egyptians through its first-born” referred to as a “great miracle,” implying that it was greater than others? Also, why is the miracle expressly related to Shabbos — “It was instituted that this miracle be remembered in future generation on Shabbos , which is therefore known as Shabbos HaGadol.”7

The purpose of the liberation from Egypt was so that “I shall take you to Myself as a nation, and I will be to you as a G‑d. You will know that I am G‑d your L-rd, who is bringing you out from under the Egyptian subjugation.”8

In other words, the revelation of G‑dliness at the time of the exodus caused Jews to be able to discern and know G‑d even when they find themselves occupied in worldly matters. Additionally, at the time G‑d gave the Torah, it allowed them to unconditionally accept His Torah and mitzvos, as the verse states:9 “When you will take the nation out of Egypt they shall serve G‑d on this mountain.”

Jews were thus expected to reveal G‑dliness in a permanent and ongoing manner within this world, through their spiritual service. Thus the exodus and receiving the Torah culminated in the building of the Mishkan , a physical place wherein G‑d would “dwell among them.”10 This came to fruition in an even more permanent manner with the erection of the Beis HaMikdash , the completed state of which will be the third and eternal Beis HaMikdash.

This explains why the exodus came about specifically through miracles, for only a supernatural event manifests G‑d’s unlimited ability. This lets a person perceive that G‑d is the supreme master of nature, doing with it as He wills. In turn, this enabled the Jews to free themselves from the bonds and limitations of the mundane as a whole, and from Egyptian exile in particular.

The greatness of “smiting the Egyptians through its first-born,” as well as its connection to Shabbos HaGadol , will be understood accordingly.

The “miracle of miracles” of “smiting the Egyptians through its first-born,” lies in the fact that only the revelation of G‑dliness as it wholly transcends nature could cause the first-born Egyptians — the mightiest11 force of evil — to smite Egypt.

A miracle such as this is labeled a “great miracle,” one that serves as the pivotal event through which “the redemption and miracles [of the exodus] began.”

The commemoration of this wonder was established on Shabbos, for Shabbos is not only the day of the week during which we venerate G‑d as He rested from the six days of creation, removed from and towering above nature, but also because Shabbos is related to the eternal redemption, a time “composed entirely of Shabbos and tranquillity.”12

This theme is stressed to an even greater degree when Shabbos HaGadol occurs on the Shabbos on which we read the Torah portion Tzav , concerning which our Sages say:13 “The term tzav , command, means: perform with alacrity — now, and for all future generations.”

This further emphasizes the fact that eternity — that which transcends time and nature — descends within and permeates this finite and time-bound world.

Based on Sefer HaSichos 5751, Vol. I, pp. 395 -409.