Leprosy is the major topic of this week's portion. We hear about the purification ritual for a recovering leper (Leviticus 14:1-20), the more economic purification ritual for the poorer leper (Leviticus 14:21-32), and the procedure for dealing with a house that displays signs of leprosy (Leviticus 14:33-57). But this week's regularly scheduled Torah portion is, in many ways, overshadowed by the additional reading we add in honor of Shabbat Hagadol, or the "Great Shabbat," which occurs the weekend before Passover every year. The additional Torah reading is from Exodus 12:1-20, and it describes the bringing of the paschal offering on the night before the Exodus. The people of Israel are commanded to set aside a young male sheep on the 10th day of the month of Nissan, watch over it until the 14th of Nissan, and then sacrifice the animal, roast it whole, and eat it with matzah and bitter herbs (Exodus 12: 3-10). The blood of the sheep is to be spread on the doorposts to protect the Israelites from the plague that will kill the firstborns of Egypt (Exodus 12:7, 13). The verses that describe these events are charged with historical consciousness, as the Israelites are told, "This day shall be for you a remembrance, and you shall celebrate it as a holiday before God, throughout the generations you shall celebrate it" (Exodus 12:14). The Midrash Rabbah comments that the Israelites could not leave until this paschal offering was brought (Shmot Rabbah 15:3). What is the significance of this sacrifice, and why is it specifically the precursor of the Exodus?

In order to explore these questions, we must first understand the background of the Israelites' stay in Egypt. According to traditional estimates, the people of Israel resided in Egypt for 210 years, and accordingly they became steeped in Egyptian culture. In the book of Ezekiel, God remembers appealing to the people of Israel, "Cast away, every one of you, the detestable things that you are drawn to and do not defile yourselves with the idolatries of Egypt.... But they defied Me and refused to listen to Me" (Ezekiel 20:7-8). The Midrash Rabbah notes that it was very difficult for the Israelites to abandon the Egyptian deities. And so before they could physically leave Egypt, they first had to abandon the Egyptian culture and recognize that they were a nation apart.

God teaches the Israelites that they are distinct from the Egyptians through the mechanism of the Ten Plagues. In announcing the fourth plague, that of wild beasts, God declares, "And on this day I will miraculously set apart the land of Goshen upon which my people dwell in that there will be no wild beasts there.... I will set redemption between My people and your people" (Exodus 8:18 ). During the fifth plague, that of pestilence, God again proclaims that a "miraculous division" will be made between the flocks of Israel and the flocks of Egypt (Exodus 9:5). The plagues introduce and reinforce the idea that Egypt and Israel are separate peoples with separate destinies.

Interestingly, this language of separation does not begin until the fourth plague. Ibn Ezra, the classical Bible commentator, concludes from this that the first three plagues--those of blood, frogs, and lice--affected both Egyptians and Israelites indiscriminately. It has been suggested that the first three plagues were specifically directed at undermining Egyptian gods. Egypt worshipped the Nile, a symbol of fertility, which is subverted in the first plague into a bloody symbol of death. The Egyptians had a fertility goddess with the body of a woman and the head of a frog; suddenly, in the second plague, the country is overrun with frogs reproducing at a fantastic rate. The third plague, that of lice, was specifically aimed at the Egyptian cultic elite, because the ordinary commoners were generally covered in lice anyway (from Binah B'Mikrah on Parshat Va'era). Since the Israelites had been worshipping Egypt's gods as well, both the Israelites and the Egyptians were afflicted by these first three plagues.

Beginning with the fourth plague, though, God begins to teach the Israelites of their separate and unique status. This process continues throughout the rest of the plagues, and its climax is the paschal offering. The Egyptians worshipped sheep and considered it an abomination to sacrifice them. In this ultimate act of cultural independence, the Israelites publicly sacrifice the gods of Egypt, and in this way proclaim their own identity. Only when the Israelites realize that they are a separate nation are they able to leave Egypt to pursue their own destiny. It is this birth of national consciousness that we celebrate this Shabbat.