Massuet remarks here that Irenæus makes a reference to the apocryphal book of Enoch, in which this history is contained. It was the belief of the later Jews, followed by the Christian fathers, that “the sons of God” (Gen. vi. 2) who took wives of the daughters of men, were the apostate angels. The LXX. translation of that passage accords with this view. See the articles “Enoch,” “Enoch, Book of,” in Smith’s Dictionary of the Bible. [See Paradise Lost, b. i. 323–431.]