PURIFICATION: PURIFICATION IN JUDAISM The concept of purity represents one of the cornerstones of Jewish religiosity from its earliest articulation in biblical literature. Indeed, the ideal of attaining purity by purification from the various kinds of impurities enumerated in the Book of Leviticus forms an integral part of the notion of holiness in that book, as well as in later Jewish sources. At the same time, purity is not a uniform concept. Source for information on Purification: Purification in Judaism: Encyclopedia of Religion dictionary.