Well, Sailhamer may write long introductions, but he sure knows hows to get you hooked. When considering the composition of the three legal codes of the Pentateuch he argues that the Mosaic law was added to the Sinai covenant as a consequence of Israel's transgressions. (p42) So the structure of Exodus-Leviticus looks a little like this:
- Sinai Covenant, Ex 19-31, original covenant >>>
- Golden calf incident, Ex 32-33, priestly indiscretion >>>
- Priestly Code, Ex 35- Lev16, extra laws >>>
- Goat idols, Lev 17:1-9, popular indiscretion >>>
- Holiness code, Lev17-25, extra laws
Personally, as a father of young children, I like this scheme because it is true to life. At home we do not create new rules till the kids' behaviour demands it. In our house, as in Sailhamer's scheme, rules are purely pedagogical. The default setting is freedom and grace. However, the jury is out at this stage over whether or not this really works as an explanation of the laws in Exodus-Leviticus.