There are four distinct, self-contained collections of laws found in the Hebrew Pentateuch – the "books of Moses": Genesis, Exodus, Leviticus, Numbers, and Deuteronomy. Each of these collections is clearly delineated by (1) opening and closing formulae, (2) repetitive vocabulary – key words and phrases that are regularly used in introductory formulae, transitional passages, and points of particular emphasis – and (3) recurring themes – large overall literary motifs that tie the individual laws together into a cohesive whole.
These four legal collections are
- The Decalogue (The Ten Commandments) – Exodus 20
- The Book of the Covenant – Exodus 21-23
- The Holiness Code – Leviticus 17-26
- The Deuteronomic Code – Deuteronomy 12-26
In the Pentateuch, these law collections are nestled within lengthy narrative passages that tell the story of ancient Israel's exodus from Egypt, initial reception of the law at Mount Sinai, generational wandering in the desert, and impending entrance into Canaan. Along with these narratives are a smorgasbord of rules and regulations which are not a coherent whole, but rather a compilation of loosely connected laws. Since most of these laws reflect a priestly outlook focusing on Hebrew worship, sanctuaries, sacrifices, and Levitical oversight, this loose conglomeration is often referred to as the "Priestly Code." This name should not be taken to suggest that these laws have the same literary unity and cohesion as the Decalogue, the Book of the Covenant, the Holiness Code, and the Deuteronomic Code.
Each of the collected law books – the Decalogue, the Book of the Covenant, the Holiness Code, and the Deuteronomic Code – reveals clues as to the time and social setting of their collection. Each collection seems to codify – place in written form – laws that speak to a specific and changing historical setting. Clearly, these collections are often built around existing and, in some cases, much earlier individual laws. Equally true, there seems to be a progression among the law "books" with later collections building on earlier collections, revising more primitive laws to apply them to changing social and economic realities.
This trajectory – devotion to early law codes that are revisited and re-applied in future generations – is exactly the same trajectory we see in the later "oral" law and the centuries-long debates among the Jewish rabbis about when and where and how ancient Israel's laws are to be applied in later generations.