"HaShem said to Moshe and Aharon in the land of Egypt saying: 'This month is to be the beginning of months to you; it is to be for you the first of the months of the year. Speak to all the community of Israel, saying: "On the tenth of this month, they will take to themselves, each man, a lamb for each father's house, a lamb for the house." ' " (Exodus 12:1-3)
With these words, God began the final stage of redemption from Egypt. Four hundred and thirty years after God had decreed to Avraham that his descendants would be enslaved in an alien land, that He would judge the nation that enslaved them, and that they w
Our very first national mitzvah is to determine our own calendar.
ould subsequently leave with great wealth (Genesis 15:13-14); four hundred years after the countdown began with the birth of Yitschak; 232 years after Yosef was dragged down to Egypt in chains; 210 years after Ya'akov and his family came down to Egypt; after the family had grown into a nation living in the midst of another nation; when the nation of Israel had sunk to the 49th level of impurity, one bare step above the abyss from which there could be no return, with Israel mired in the spiritual filth of Egyptian idolatry; with nine plagues already seared into the Jews' and Egyptians' memory, and the tenth and most horrendous plague of all still to come; immediately after Moshe warned Pharaoh of this final plague - now, in the month of Nissan, the nation of Israel stood at the gates of freedom.

Our very first national mitzvah is to determine our own calendar.
ould subsequently leave with great wealth (Genesis 15:13-14); four hundred years after the countdown began with the birth of Yitschak; 232 years after Yosef was dragged down to Egypt in chains; 210 years after Ya'akov and his family came down to Egypt; after the family had grown into a nation living in the midst of another nation; when the nation of Israel had sunk to the 49th level of impurity, one bare step above the abyss from which there could be no return, with Israel mired in the spiritual filth of Egyptian idolatry; with nine plagues already seared into the Jews' and Egyptians' memory, and the tenth and most horrendous plague of all still to come; immediately after Moshe warned Pharaoh of this final plague - now, in the month of Nissan, the nation of Israel stood at the gates of freedom. Of course, the corollary of freedom is responsibility. A slave, by the very definition, has neither freedom nor responsibility. Commensurate with this, our national liberation was heralded not by unbridled revelry, but by mitzvot - the responsibility to obey God's commandments, responsibility for our actions: the passage "...this month is to be the beginning of months for you..." constitutes the first mitzvah given to us as a nation, the command to establish a calendar, to start counting the months from the month of Aviv (Nissan).
It is significant that our very first national mitzvah is to determine our own calendar: "From now onwards, the months will be yours, to do during them whatever you desire; but in the days of slavery, your days were not yours; rather, they were subjugated to other people and their desires. Therefore, ‘it is to be for you the first of the months of the year,' because in this month your freedom of choice begins to be actualized." (Sforno on Exodus 12:2)
A calendar is almost irrelevant to the slave: he sleeps and wakes, eats and works, lives his entire existence, according to his master's whim. Only a free person can determine his own schedule, and only a free nation can determine its own calendar. The responsibility that God thrust upon us with this first command shows the measure of trust that he placed in us: "He taught them the faces of the moon, then said to them: 'Until now, I Myself determined which years were leap years. And behold, I have given that responsibility to you: from now, you begin to count.' " (Tanchuma on Bo 6)
The second mitzvah with which God charged us was equally a demonstration of freedom from Egyptian slavery: "On the tenth of this month, they will take to themselves - each man - a lamb for each father's house." The sheep which they were commanded to slaughter was the Egyptian deity; they were commanded to take it on the tenth of the month, and keep it until the fourteenth (Exodus 12:6), during which time the Egyptians would per force become aware of what their erstwhile slaves were doing to their god; they were commanded to roast it whole - not cooked in a pot to hide it, nor carved up to make it unrecognizable - to make their defiance of this Egyptian deity as blatant as possible; and they were commanded to daub its blood on the two doorposts and the lintel of the houses, ensuring that it was blatantly visible to the Egyptians. 
The Jews were to make their defiance of the Egyptian deity as blatant as possible.


The Jews were to make their defiance of the Egyptian deity as blatant as possible.

For a nation that had spent its entire living memory under Egyptian subjugation, this public violation of the Egyptian religion demanded immense faith in HaShem. It was also a catharsis, demonstrating complete freedom from the former Egyptian slave owners.
This was the birth of the Jewish nation, allegorized so graphically and so movingly: "As for the place of your birth - on the day of your birth, your umbilical cord was not cut, nor were you washed in water to sooth you, nor were you salted [to make your flesh firm - Rashi], nor were you swaddled. No, I had pity on you, to do any of these for you.... Then, I passed above you, and I saw you wallowing in your blood. And I said to you, 'In your blood shall you live;' and I said to you, 'In your blood shall you live.' " (Ezekiel 16:4- 6)
We broke free of Egyptian slavery in the merit of two mitzvot, both of which demonstrated our faith in God, both of which involved blood: "When the memory of the covenant with your forefathers came before me, I revealed Myself to redeem you, because I realized how you were suffering in Egyptian subjugation. And I said to you, 'Because of the blood of circumcision I will have compassion on you;' and I said to you, 'Because of the blood of the Pesach sacrifice I will redeem you.' " (Targum on Ezekiel 16:6)
Today, as we stand at the threshold of the final redemption, this message is more relevant, certainly more immediate, than ever before. "In the month of Nissan we were redeemed from Egypt, and in the month of Nissan we will again be redeemed in the future." (Rosh Hashanah 11a) A few more mitzvot, a little more self-sacrifice, and perhaps the Pesach sacrifice this year on the fourteenth of Nissan will be on the Temple Mount. We are standing at the gates of the final redemption and we need the faith in God just to take the final few steps.