Leviticus 17-27, called the “Holiness Code” by scholars, is distinguished from the rest of the book by its particular language and concerns.
Leviticus 17-26 (and often including chapter 27) are commonly called the “Holiness Code” by biblical scholars. These chapters are marked by a concern for Holy is a term that originally meant set apart for the worship or service of God. While the term may refer to people, objects, time, or places, holiness in Judaism and Christianity primarily denotes the realm of the divine living on the part of the people rather than a concern with sacrificial systems or ritual purity, as are the first sixteen chapters of the book. The holy living to which the Holiness Code calls the people is to be exemplified in all arenas of life–economic, social, sexual, familial. Leviticus 19:2 provides the foundation for this call to holiness: “You shall be holy, for I the LORD your God am holy” (compare 20:7, 26; 21:8). The refrain that marks these chapters seems to be a “shorthand” way of saying the same thing: “I am the LORD” or “I am the LORD your God.” (These two phrases occur only two times in Leviticus 1-16, but forty-seven times in chapters 17-26.) The people are to be holy because the Lord their God is holy. Their holiness is to mirror God’s.
The composition of the Holiness Code is attributed to a circle within the larger priestly tradition, the so-called Holiness source or school (H). Recent scholarship has argued that the Holiness Code was written after much of the rest of the P material, and that it is essentially an inner-priestly response to the concerns of the eighth century B.C.E. prophets for social justice and for a reformation of the priestly religious establishment (see Isaiah, son of Amoz, who prophesied in Jerusalem, is included among the prophets of the eighth century B.C.E. (along with Amos, Hosea, and Micah)--preachers who boldly proclaimed God's word of judgment against the economic, social, and religious disorders of their time. 1:10-17; Prophet to the northern kingdom who condemned Israel's oppression of the poor, calling for justice to "roll down like waters." 2:6-16; and Micah 3:9-12). There is still considerable scholarly debate over the relative antiquity of H and P. Nevertheless, there is consensus on the existence of a distinct Holiness Code in Leviticus, marked by the refrain, “I am the LORD,” and by a concern with holiness, with moral and ethical living on the part of the Israelites.