The first two portions of the book of Exodus, (1) Shemot and (2) Va’era, spoke of the preparations for leaving Egypt, while the next two, (3) Bo and (4) Beshalach, will describe the Exodus as it actually occurred. At the same time, portion Bo considers the Exodus from an internal point of view (and in this sense it is “the Torah of Moses”), while Beshalach gives us an external perspective (“the Torah of Aaron”).
The name of this portion, Bo, is taken from its opening words, “Then the Lord said to Moses: Go to Pharaoh.” But the name also alludes to the idea that the Jewish people had to go down to Egypt in order to extract from it what would become a part of their own spiritual heritage, the Divine sparks that were contained there. Egypt, as already noted, was the most highly developed civilization of that time. The Exodus of the Jews therefore had to happen only there, at the epicenter of the world’s civilizations, so that through the Jews the greatness of Egypt could become a foundation for the spiritual advancement of mankind.
The main theme of the Bo portion is the internal aspect of the Exodus – the Jews’ awareness of themselves as a distinct people, now separated from Egypt. Among Bo’s central themes are the change to a uniquely Jewish calendar, the Passover Seder, and the accession of a significant number of Egyptians to the Jewish Exodus. All of these – the calendar, the Passover Seder, and the process of giyyur (conversion to Judaism) – are fundamental concepts of Jewish identity.
The commandment to establish a calendar is the very first commandment that the Jewish people receive as a nation. The calendar and holidays of every society reflect its basic value system, its “minimal catechism” that everyone is expected and assumed to know. And this is of course true of Jewish society as well. The arrangement of the Jewish lunar-solar calendar itself speaks of the Jewish mission in the world.
Egypt’s calendar was solar. It was adopted first by the Greeks and Romans, followed by European Christian civilization. The ancient world of the east, as represented fundamentally by Babylon, originally had a lunar calendar; Islamic civilization, with its lunar calendar, is the heir to Babylon in that regard. In contrast, the Jews upon leaving Egypt received a lunar-solar calendar, which integrates the western and eastern features of the ancient “western” world.
The Jewish nation transitioned to its own calendar only two weeks before the Exodus: “The Lord said to Moses and Aaron in the land of Egypt: This month shall mark for you the beginning of the months; it shall be the first of the months of the year for you” (12:1-2). The month of Nisan had just begun, and that beginning had to be established according to the Jewish, not Egyptian, calendar. This had the immediate effect of further distancing the Jews from the Egyptian way of life. The new calendar oriented the Jewish nation not only to its freedom from Egypt, but also to realizing its uniquely universal role among the peoples of the world, by serving as the bridge between Babylon and Egypt.
Portion Bo‘s second topic is the Passover Seder. Passover celebrates the birth of the Jewish people, and sets the goal for all future Jewish life, namely: to bring humanity ever closer to the Almighty. In future times Passover and the Exodus would determine the trajectory of the world’s development and epitomize the idea of progress in the worldview of all of Western civilization.
Time in idolatrous culture is cyclical: Birth, maturation, aging, dying, and new birth – all these comprise the immutable circle of life. But in Jewish culture, time is a vector that emerges when the entire world pursues a common goal. The Exodus from Egypt created this Jewish vector of time. The Exodus determines that the universe has a purpose, that time, rather than being cyclical, has direction. In this sense the Exodus changed not only Jewish history but the worldview of mankind as a whole. From Judaism, both Christianity and Islam inherited the vector of time, as well as the sense of purpose and meaning in history, and conveyed that sense to most of the world’s population.
Finally, in the third topic of the Bo portion we learn that many foreigners joined the Jews upon their departure from Egypt, and became a part of the Jewish nation. This affiliation established the structure of our people for all time. The Jewish people are an open community that willingly receives new members. Any person from anywhere on earth who wishes to become a Jew can do so.
In this sense, the Jews are not a race. But, on the other hand, by no means does this imply that the Jewish people are to be considered a “congregation of proselytes” or a purely religious community. The descendants of Abraham, Isaac and Jacob are the core of the Jewish people – proselytes join this already-existing nation. Although, according to the laws of Judaism, every boundary between those two is erased, which means that proselytes become full-fledged Jews, the ethnic core is nonetheless also preserved for all centuries to our time.
As a general rule, based on genetic research, we can say that two-thirds of the Jewish people today are descendants of the ancient Jewish nation, and one-third are those who have joined it later, or are their descendants. The Jewish people continue to retain their national identity and self-awareness, and to transmit their ancient Jewish heritage along lines of Jewish birth. But at the same time, Judaism and the Jewish nation are open to accession. This combination of tradition and openness, a hallmark of the Jewish people since their very creation, is one of their most important features.
 A small number of commandments had been given earlier to the Patriarchs as individuals, but the commandment to establish a calendar is the first commandment given by God to the Jewish nation as a whole.