Genesis 5:28

I am aware that the Scripture of Enoch, which has assigned this order (of action) to angels, is not received by some, because it is not admitted into the Jewish canon either. I suppose they did not think that, having been published before the deluge, it could have safely survived that world-wide calamity, the abolisher of all things. If that is the reason (for rejecting it), let them recall to their memory that Noah, the survivor of the deluge, was the great-grandson of Enoch himself; and he, of course, had heard and remembered, from domestic renown and hereditary tradition, concerning his own great-grandfather’s “grace in the sight of God,” and concerning all his preachings; since Enoch had given no other charge to Methuselah than that he should hand on the knowledge of them to his posterity. …

Serenus : You have propounded two not unimportant questions, to which I will reply, to the best of my ability, in the order in which you have raised them. We cannot possibly believe that spiritual existences can have carnal intercourse with women. But if this could ever have literally happened how is it that it does not now also sometimes take place, and that we do not see some in the same way born of women by the agency of demons without intercourse with men? especially when it is clear that they delight in the pollution of lust, which they would certainly prefer to bring about through their own agency rather than through that of men, if they could possibly manage it, as Ecclesiastes declares: “What is it that hath been? The same that is. And what is it that hath been done? The same that is done. …