The eleven weekly portions of the book of Exodus can be grouped into pairs (except for the ninth portion, Ki Tissa, which deals with a national crisis). Thus, the theme of each such pair is considered from two different points of view. This understanding of the structure of the books of the Torah according to their weekly divisions was elaborated by Rabbi Zvi Yehuda Kook.
It is well known that our division of the Torah into weekly portions originated in Babylonia. In contrast, the inhabitants of the Land of Israel, in antiquity, used a different system for dividing the Torah into weekly Shabbat readings, because they completed the reading of the Torah only twice in seven years, rather than once annually as we do today. The Babylonian system divided the Torah into fifty-four weekly portions, a number that approximates the number of weeks in a typical (average) Jewish year. It is the system of weekly divisions still in use today.
Although the division of the five books of the Torah into weekly portions is usually perceived as merely a technical matter, bearing no special meaning in and of itself, Rabbi Z. Y. Kook thought otherwise. He considered these divisions a part of the Babylonian Talmudic tradition and believed that ipso facto there must be a definite meaning to them.
In the Book of Exodus in particular (and later, in the Book of Leviticus as well), the pairing of the weekly portions represents the counterpoint of Moses’ and Aaron’s perspectives. These differences, especially pronounced in relation to the Tabernacle, will be covered in detail below, when we compare portions (7) Terumah, and (8) Tetsaveh. But the same contrast is also noticeable in the earlier portions of this book of Exodus.
The “Moses” portion of each pair always refers to the “inner” side of what is happening, as they describe the inner essence of things and events. In contrast, the “Aaron” portion of each pair is more oriented to externals, that is, to the manner in which those same things and events find expression in the larger world. We will see this contrast below, in the comparison of portions (1) Shemot, and (2) Va’era; in (3) Bo, and (4) Beshalach; and then in (5) Yitro, and (6) Mishpatim.
Creation and Revelation are two fundamentally Divine actions. Creation of physical world is meant to conceal God, while the purpose of Revelation is to reveal Him. Genesis is the book of Creation – the creation of the world and the foundations of the future Jewish people. The Book of Exodus is the book of Revelation – revelation in the process of the Exodus from Egypt, revelation in the giving of the Torah at Mount Sinai, and revelation through the Divine presence in the Tabernacle.
For many people, it is a simple matter to recognize Divine Creation in the world, but very difficult to recognize Revelation. Also, Revelation is more important for our religious life, because it demonstrates our personal connection with God and His direct involvement in the events happening around us. But in the act of Creation, God’s concern for man is not manifested explicitly – He creates the world and sets it in motion, but then it just “takes its course,” as it were. In the act of Revelation, however, God’s care and personal connection come to the fore. In this sense, Revelation is more significant for us than Creation. Acknowledging Revelation is thus the next level of religious attainment, after recognition of Creation.
The Midrash notes that the Torah begins with the word “Bereshit,” “In the beginning,” whose first letter is bet, the second letter of the Hebrew alphabet. The Midrash explains that alef, the first letter of the alphabet, had asked God to be the Torah’s opening letter, but God declined, promising instead that the time would come for the phrase Anochi HaShem Elohecha, “I the Lord am your God who brought you out of the land of Egypt,” to appear (20:2, the opening words of the Ten Commandments). There, alef would occupy the opening position. In other words, bet represents Creation, and alef – Revelation.
Creation must begin with bet, the second letter, because in Creation there must be not only a single tendency, but a variety of different options for understanding. Since Creation must conceal God’s presence, its realization must allow a person to choose whether he wants to feel a connection with God in his life, or to refuse that connection. This is because only when a person has free choice can he make his own decision.
But as concerns Revelation, the situation is different. Revelation is a direct connection with the Divine Essence that is being revealed with such absolute immediacy that it leaves no room whatsoever for doubt. This Unity and Oneness is expressed by alef, the first letter of the Hebrew alphabet.
Creation produces a world in which God is hidden. When we observe the universe or explore it solely from a scientific perspective, we cannot find meaning or purpose in it, for these cannot be inferred from objective study of the world around us. This missing element in the universe gives us Revelation, whose task is to demonstrate that there is meaning and purpose in the world.
It is no coincidence that the Book of Revelation is also called “Shemot,” which means “names.” We have already noted earlier that the Hebrew word shem, “name,” denotes not just the essence of a thing, but its objective and purpose. If the book of Genesis describes the structure of the world, then the Book of Names speaks of the purpose and meaning of the universe.
 The book of Genesis is likewise composed of paired weekly portions, while the remaining books – Leviticus, Numbers, and Deuteronomy – are constructed according to a different scheme, as we shall discuss in the Bible Dynamics commentary on these books later.
 The purpose of that design was to allow the conclusion of one out of every two such cycles to coincide with the end of the Shemittah year, which itself repeats at seven-year intervals. The Torah prescribes (Deut. 31:10) that the commandment of Hakhel be performed on the festival of Sukkot following the conclusion of each Shemittah year. Because Hakhel (the word means “communal gathering”) was observed by a public reading of the Torah in the Temple in Jerusalem, it was deemed appropriate that the weekly Torah-reading cycle in the Land of Israel should coincide likewise with the Shemittah cycle (albeit repeating twice as often as that the latter does).
 This point is very clearly demonstrated, for example, by the Hebrew term “le‑shem,” which literally translated means “for the name of,” but whose actual meaning is “for the sake of.” E.g., le-shem mitzvah, “for the sake of [fulfilling] a commandment.”