On the Shabbat before the Exodus--Nissan 10th on that year--the first-born of Egypt, who occupied the senior positions in the priesthood and government, fought a bloody battle with Pharaoh's troops, in an effort to secure the release of the Israelites and prevent the Plague of the Firstborn. This "great miracle" is commemorated each year on the Shabbat before Passover, which is therefore called Shabbat HaGadol, "The Great Shabbat." (This is one of the rare instances in which a commemorative date in the Jewish calendar is set by the day of the week rather than the day of the month.)
For more on the war of the Firstborn, see here.
Miriam, the sister of Moses, passed away at the age of 126 on the 10th of Nissan of the year 2487 from creation (1274 BCE) -- 39 years after the Exodus and exactly one year before the Children of Israel entered the Holy Land. It is in deference to her passing that the "Great Shabbat" is commemorated on the Shabbat before Passover rather than the calendar date of the miracle's occurence, Nissan 10.
Link: About Miriam.
Three days after the two spies dispatched by Joshua scouted the city of Jericho (see entry for "Nissan 7" above), the children of Israel were ready to enter the land promised by G-d to their ancestors as their eternal heritage. As they approached the Jordan with the Holy Ark carried by the Kohanim (priests) in their lead, the river parted for them, as the waters of the Red Sea had split when their fathers and mothers marched out of Egypt 40 years earlier. (Joshua 4)
In today's "Nasi" reading (see "Nasi of the Day" in Nissan 1), we read of the gift bought by the nasi of the tribe of Dan, Achiezer ben Amishadai, for the inauguration of the Mishkan.
The Shabbat before Passover is termed Shabbat HaGadol ("The Great Shabbat") in commemoration of the "great miracle" that happened in Egypt on this day, heralding the Exodus from Egypt five days later (see "Today in Jewish Hstory"). Shabbat HaGadol customs include reading a portion of the Haggadah (from "Avadim hayinu..." to "...al kol avonotainu"), which tells the story of the Exodus; it is also customary that the rabbi of the community delivers a lecture in which he elaborates on the laws of Passover and their significance, in preparation for the festival.
Of the 54 parshiot of the Five Books of Moses, only one is named after a woman. It is called “The Life of Sarah.”
It opens by informing us that Sarah has died.
Yes, this is the life of Sarah. Her true life. Because only in her passing was Sarah’s life fulfilled.
During her lifetime, she and her husband Abraham surveyed the land promised to their children. Only once Sarah died did Abraham make his first actual purchase, publicly and with full payment. Sarah’s burial plot and its accompanying field in Hebron mark the seminal point of the Land of Israel.
During her lifetime, Sarah had only one child, who remained single. From where would come the “offspring more numerous than the stars” that G‑d had promised? With Sarah’s passing, the match between Isaac and Rebecca was made, a woman much like Sarah, through whom the Jewish people would become a reality.
During Sarah’s lifetime, Abraham was not able to guide Ishmael. By divine command, he was compelled to harken to Sarah, who witnessed Ishmael’s corruptive influence and demanded he be sent away. By the end of the parashah, Abraham is following in the ways of Sarah with the rest of his children. Even Ishmael has repented and accepted Isaac as the true heir of Abraham.
It was after Sarah’s passing that Abraham’s vision began to emerge into reality in this world—through the work of Sarah.
This is true life—a life not confined to the years of a physical body, but a life that becomes yet more real after it is released from those confines, and continues to be felt more and more with every year that passes.
Such is the life of a mother. While the rest of us live within a moment that has already disappeared, a mother gives life, nurtures life, and guides that life into eternity.