fact, several elements of the story of the Watchers are shaped by the effect of a gentile Mesopotamian background of the work. Genealogical impurity (the Giants born from the relations of the Watchers and the earthly women) is the first level of the systematic spread of the evil in the world. Elements related to impurity, sin, and intermarriage were those necessary for the self-determination of a group, the keeping of shabbat and special purity rules being the qualities that distinguished the exiles
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