Scholars have defined holiness in many ways. These range from the vague and ethereal adjective "numinous" to practical matters of ritual purity. When a bunch of grain and God can both be called "holy, " how should we understand the elusive meaning of this word? Harrington presents an in-depth exploration of holiness in the context of rabbinic Judaism based on a holistic yet detailed understanding of the relevant texts and Scripture. The rabbinic concept of holiness is placed along other notions of the sacred in the Graeco-Roman world, providing a much-needed comparative view of this core subject during a key period in the development of the Jewish religion.