Last week's Torah portion (Va'era) reported how Pharaoh refused to listen to Moses' pleas for Israel's freedom, despite seven devastating plagues that came upon Egypt in God's Name (יהוה). In this week's portion (Bo), the battle between God and Pharaoh comes to a dramatic conclusion. The last three of the ten plagues are unleashed upon Egypt: a swarm of locusts devoured all the crops and greenery; a palpable darkness enveloped the land for three days and nights; and all the firstborn of Egypt were killed at the stroke of midnight of the 15th of the month of Nisan...
Before the final plague, God instructed the Jewish people to establish a new calendar based on the sighting of the new moon of spring. On the tenth day of that month, God told the people to acquire a "Passover offering" to Him, namely an unblemished lamb (or goat), one for each household. On the 14th of that month ("between the evenings") the animal would be slaughtered and its blood sprinkled on the doorposts and lintel of every Israelite home, so that God would "pass over" these dwellings when He came to kill the Egyptian firstborn that night. The roasted meat of the offering was to be eaten that night with unleavened bread (matzah) and bitter herbs (maror). God then commanded the Israelites to observe a seven-day "festival of matzah" to commemorate the Exodus for all subsequent generations.
Just before the final plague was delivered, God instructed the Israelites to ask their Egyptian neighbors for gold, silver and jewelry, thereby plundering Egypt of its wealth. The death of the firstborn at last broke Pharaoh's resistance and he finally allowed the Israelites to depart. Because they left in great haste there was no time for their dough to rise. The Torah states that there were 600,000 adult men who left Egypt, along with the women, children, and a "mixed multitude" of other Egyptian slaves who tagged along.
The Israelites were commanded to consecrate all the firstborn to God and to commemorate the anniversary of the Exodus each year by celebrating the LORD's Passover in conjunction with the Feast of Unleavened Bread. During this time they were to remove all leaven from their homes for seven days, eat matzah, and retell the story of their redemption to their children. The portion ends with the commandment to wear tefillin (phylacteries) on the arm and head as a reminder of how the LORD saved the Israelites from their bondage in Egypt.