"... In 1 Enoch 6–11, we find a composite unit whose exuberant polysemy evades any easy explanation. This unit includes three descriptions of the Watchers’ transgressions, each with a different focus. The first, 1 Enoch 6–7, most closely follows Genesis 6:1–4: chapter 6 begins with a paraphrase of Genesis 6:1, followed by a description of the Watcher Semihazah convincing a group of angels to swear an oath to travel to the earth and beget children with the “daughters of men” (verses 3–6). Chapter 7 tells of their cohabitation and defilement with human women, to whom they teach magical and medicinal arts (v.1) and from whom Giants are born (verse 2). The great violence of the Giants is then described (verse 3; compare Genesis 6:11), culminating in the outcry of the earth against them (verse 4) ... It is striking, for instance, that all three summaries of angelic sin in this unit culminate with descriptions of the violence of the Giants against the creatures of the earth (7:3–5; 8:4; 9:9) and the resulting outcry of either the earth itself (7:6) or humankind (8:4; 9:10). In addition, three themes are highlighted throughout: [1] the dangers of sexual impurity, [2] the corrupting potential of knowledge, and [3] the antediluvian proliferation of violence ..."

Reed, Annette Yoshiko Fallen Angels and the History of Judaism and Christianity: The Reception of Enochic Literature (pp. 27-30) Cambridge University Press, 2005