We noticed that the structure of the Book of Leviticus itself replicates the three-fold structure of plain/mountainside/mountain-top. The first two chapters deal with whole-burnt offerings, and take place at the altar, which in the description given of the mountain in Exodus 19 and 24 sits precisely at the boundary between the plain and the mountainside. In the description in Exodus, the people must remain on the plain, and not touch the mountain. The seventy elders eat in the presence of God on the side of the mountain (Exodus 24:11), and Moses alone goes to the mountain top. In Leviticus, the people do not go past the altar toward the Tent. When the offering involves a portion for the priests to eat (as in the cereal burnt offering), the priests eat in the holy precincts (the mountainside).
Beginning in Chapter Four of Leviticus, we come to the regulations regarding sin offerings. In these, the priest is to take some of the blood of the offered animals, and smear it on the horns of the altar of incense, just outside the holy of holies. The incense provides the cloud which covered the mountain top when Moses went up. The priest is also to sprinkle some of the blood toward the curtain which hides the holy chamber. The rest gets poured on the altar outside the Tent, thereby re-establishing the connection between God and the people which had been broken by the sin, whatever it was.
As for inadvertent sins, what are we to make of that? For us, sin and intention go hand in hand. If I did something inadvertently, it’s not a sin. Leviticus and all post Exilic religion had suppressed the use of divination. There are no oracles to be consulted, lots to be thrown, mediums to consult. So, when something goes wrong in community, how do you figure out what? In most religions, there is some kind of rite for establishing blame. Look at the liver of an animal to determine who broke contract, or cursed someone else. Read the tea leaves, cast the sacred circle (or pentagram, or whatever). Leviticus doesn’t allow this. But, still, if something is wrong in the community, there must have been a sin. Leviticus leaves the discover of that vague: If a person should discover he or she sinned inadvertently . . .
Then, there is plenty of ritual described for re-establishing the broken connection, and almost all of it involves blood. Blood provides the link that re-establishes the kinship between God and the people. The bullock burned outside the camp expiates whatever residue of the sin remains.
The special cases interestingly involved the refusal to testify (since there is no other way to determine guilt), and the confusion of property and ownership, which functions like the confusion of lineage. Blood cleans it up.