Schwartz Baruch J. Schwartz & Wright David P. Wright 
Perspectives on Purity and Purification in the Bible [PDF ebook] 

This book is a collection of essays on purificaton and atonement in the Hebrew Bible that provides new insights into the discussion of these ideas by looking at the values of sociological and anthropological approaches to the topics. The collection also examines multivalence and polyvalence in ritual and asks to what extent it is possible to speak of the function or meaning of ritual, even within the highly systematic priestly texts.