וַיְדַבֵּר יְ-הוָה אֵלָיו מֵאֹהֶל מוֹעֵד לֵאמֹר דַּבֵּר אֶל בְּנֵי יִשְׂרָאֵל
Sefer Vayikra is certainly the most law-oriented book of the Torah. While most of the books of the Torah include a significant narrative section, Vayikra has only a few scattered narratives, all directly connected to the laws of Vayikra. Adding to the uniqueness of this characteristic, most of the laws are very ritually oriented. While this section does include plenty of ethical laws, the vast majority are concerned with rituals and worship. This peculiarity led Julius Wellhausen, the founder of modern biblical criticism, to say that Vayikra is actually a very late addition to Tanakh, a ritualistic corruption of earlier prophetic ideals. More recent scholars have concluded that this was largely a manifestation of Wellhausen’s anti-Semitic beliefs, an intended denigration of what he considered to be the most Jewish part of the Torah. In this one facet, he may have been right. Vayikra is ostensibly the most Jewish book of the Torah. Much of the laws and rites we follow on a daily basis have their roots in Sefer Vayikra. Moreover, the entirety of Sefer Vayikra, down to its very structure, expresses characteristically Jewish ideas.
Sefer Vayikra can be very neatly split into two parts, Chapters 1-16 and Chapter 17-27. These two sections each deal with their own unique subject matter, and where there is overlap, the overlapping law or idea is discussed in two very different ways. The topic of the first section is fairly easy to determine, namely the Mishkan, the Korbanot, and the people responsible for both. This also includes the various persons that are not allowed to enter the Mishkan due to temporary “impurity”, and the ways those people acquire that status. The second section, however, is a little more complex.
The second half of Vayikra jumps rapidly from topic to topic. It starts off with the laws regarding animals slaughtered outside the Mishkan, moving quickly to forbidden sexual relations and the requirement not to live like the nations that previously inhabited the Land of Israel. It also discusses the laws of the Shabbat and the Holidays as well as the laws of the Sabbatical and Jubilee years. Surprisingly, peppered throughout the expected ritual laws we find an unexpected amount of moral laws. Finally, near the end of the Sefer we find the punishments awaiting those who fail to live up to the laws of the Torah.
While the laws of the first half of Sefer Vayikra focus on the Mishkan. the proper way to act therein, and who may enter and who may not, the second half focuses on the life of Bnei Yisrael outside the Mishkan. It covers most, if not all, aspects of life. It deals with the sanctity of the People, the Land, and the special designated times of the People in the Land. Quite beautifully, the switchover from the first section to the second (in chapters 17 and 18) centers on A. The laws of slaughter outside the Mishkan, and B. The command to live differently than the nations that once lived in the Land of Israel. Slaughter outside the Mishkan means taking something that normally occurs inside the Mishkan and moving it outside. That external movement brings us outside the Mishkan and into the land, upon which Bnei Yisrael must behave according to certain moral laws.
These two sections are not simply two sets of laws put side by side, however. On the surface one might think that they both ended up in one book simply by virtue of each being too small to merit its own book. But in fact the first half of Sefer Vayikra very delicately and deliberately sets up from the second half. There are many linguistic and literary connections between the two sections, but the most significant by far are the usages of the words “מעל”, “טמא”, “טהור”, and “נדה” (in their various conjugations). All of these words possess great significance in both sections of Vayikra, but their meanings are not the same. While there are many words simply repeated in the two sections, these words are repeated with entirely different meanings. While in the first section they have an explicitly ritual connotation, in the second they assume very moralistic intentions. “Impure” becomes “Morally Corrupt”, and “Purification” becomes “Forgiveness”. Ritualistic terminology becomes Moralistic analogy. The language of the Mishkan becomes the language of the Nation in the Land.
The function of the second half of Sefer Vayikra is to take the first half and apply it to the rest of the life of Bnei Yisrael. It essentially analogizes the concepts of the Mishkan to the daily life of the people. The first half of the sefer describes the Mishkan as the dwelling place of ‘א and what that means for the people who go there. The second half of Vayikra describes the People and the Land as the dwelling place of ‘א and what that means for the actions of the people on an individual and collective basis. Just as certain actions mean that a person cannot share ‘א’s space in the Mishkan, so too certain actions mean that ‘א cannot live in the daily life of the people. The laws of Sefer Vayikra are not simply complex ritual laws. They are a description of what it means to try to live in ‘א’s world and to have Him live in yours.
 This essay draws heavily from ‘Introduction to Sefer Vayikra’, a lecture by Rav Menachem Leibtag easily locatable on www.yutorah.org, and the Jacob Milgrom’s Introduction to his commentary on Sefer Vayikra, part of the Yale Anchor Bible Series.
 Note: This paragraph is just a quick summary. There are plenty of other laws in this section, but these are some of the big ones.
 This division isn’t necessarily 100%, rather it is general trend.
 It’s worth noting that of its 51 appearances in the sefer, 49 of the uses of the phrases “אני י-הוה” are in the second half of Vayikra.