At the end of the hagada we say אז רוב ניסים הפלאת - Then [on the night of the 15th of nissan] you performed great miracles. The author of this poem goes on to enumerate the various miracles that happened on this night.
We can add another one... Rashi in Parshas Toldos [27/9] tells us that one of the two animals brought to Yitzchak Avinu by Yaakov in order to receive the brachos was a Korban Pesach. This means that the brachos were given to Yaakov on the night of the 15th. After the taking of the brachos it says that Eisav hated Yaakov and decided to kill him after Yitzchak's demise [27/41-42]. Rivka then went on to call Yaakov and tell him of Eisavs evil machinations [27/42]. Where did she call him from? Where was he?? The medrash teaches that he ran away to the beis medrash of Ever.
How illuminating! Yaakov had a task to perform. He was commanded by his mother to receive the brachos from his father. But immediately after his job was concluded he returned right to the beis medrash. From he we learn that although sometimes we are forced to close our gemaras, right after we accomplish whatever task was necessary to complete, we must return to the beis medrash. We can also speculate that Yaakov knew that Eisav was going to find out and be infuriated and he needed the merit of learning to protect him.
This was also the night that Esther called Haman and Achashveirosh to the seuda and was the beginning of the downfall of Haman [מגילה ט"ו. ד"ה ויעבר וט"ז. ד"ה לתעניתו ועיי"ש ברש"ש ובעוד אחרונים]. The downfall of the terrible "klipah" [impure spiritual husk] of Haman and his forbearers Eisav and Amalek was on this night. This was on the third day of the fast of the Jews which was an atonement for their participation in the feast of Achashveirosh [from "feast" to "fast"]. The root of the downfall of the Jews is when we feel a closeness and brotherhood with the goyim. We wanted to party with them and that resulted in the decree to wipe out all Jews [as the gemara says מפני שנהנו מסעדתו של אותו רשע] - men, women and children. The tikkun is to distance ourselves from them and their ways which was symbolized by Yaakov running [on that very night] to the Beis Medrash and the Jews fasting in atonement for their sin of proximity to the ways of the goyim and their levity. It was also the night that the Jews in Egypt ate their korban pesach - the lamb which was the god of the Egyptians. A night of separation. ליל שימורים הוא - a night we are guarded from our dangerous mimicry of gentile ways and customs. [See Harirei Kedem Vol 2 Page 126 and what I wrote at http://shmatsabaitzlusa. blogspot.co.il/2011/05/blog- post_08.html that the Korban Pesach almost has the status of a Korban Geirus].
That is what we mean when we say in the hagada והיא שעמדה לאבותינו ולנו שלא אחד בלבד עמד עלינו לכלותינו אלא שבכל דור ודור עומדים עלינו לכלותנו והקב"ה מצילנו מידם - "That" is what stood for the Jewish people that not one person alone tried to destroy us but in every generation they try to destroy us and Hashem saves us from their hand.
What is the amorphous and vague "that" [my high school English teacher got very angry when we used pronouns. She wasn't "pro-noun" but "anti-noun"..]. The simple meaning is that is refers to the promise mentioned earlier ברוך שומר הבטחתו לישראל. Blessed is He who keeps His promise to the Jews. But the Holy Books add that it is also alluding to what it says in the very same passage - that the goyim try to destroy us in every generation. Whoa! How utterly paradoxical!!:-) The very fact that the goyim try to destroy us brings to our salvation. It is when they smile at us and feign closeness and friendship that we have to worry [exhibit A - pre-war germany]. הצילני נא מיד אחי מיד עשיו - Save me from my brother, from the brotherhood and warmth of Eisav and מיד עשיו - From Eisav the murderer. If we are saved from אחי - his brotherhood and chumminess [sounds like the name of a chametz-dike cookie...] we will be saved from עשיו and the danger of his viciousness.
Pesach is a GREAT TIME to strengthen ourselves in our own Jewishness and to uproot all gentile-ness from our systems. Our self definition is strengthened every time we view ourselves and act in uniquely Jewish ways. We become less Jewish when we aspire to gain acceptance and assimilate into the greater [which is really "lesser"] world population.
A beautiful and simcha-dike chag to all:-).
[Based mostly on a sicha given by the Mori Vi-rabi The Tolna Rebbe Shlita Leil Pesach 5769]