His book deals with two major subjects: first, the Idumeans Judaizing, located in Idumea and the Yturs in the Galilee and their integrating in the Jewish society. The Judaizing action describe in the Hellenistic Historiography as an act of compulsion by the Hasmonean, in order to abase their name. Kasher argues that the judaising conducted out of good will and cooperation of the nations who judaized with the Hasmonean. He examines the consequences of the Hellenistic influence in the Idumean society, and its implications on their relations with the neighbor Jewish nation, even though in the Bible the Idumean accused in co-operation with Babylon power and the ruin of Jerusalem and the temple in the year 586 BCE.
