Eutychius (Sa‘id b. Bitriq [877-940 CE])
Annals pertaining to Gen 6:1-4
Translated from Eutychii Patriarchae Alexandrini Annales (CSCO 50, ser. arab. III, t.6; ed. L[ouis]. Cheikho; Beryti: E Typographeo Catholico, 1906), 8.22-10.4.
And Mahalalel after 165 years (LXX Gen 5:15) fathered Jared, and in the 135th year of the life of Mahalalel occurred the death of Kainan, and he was interred in the Cave of Treasures. When the time of death for Mahalalel drew nigh, he summoned his son Jared and adjured him by the blood of Abel not to allow any of his family to descend from the mountain to (mingle with) the progeny of Cain the accursed murderer. And the total lifespan of Mahalalel was 895 years.
And Jared after 162 years fathered Enoch. Now as for the progeny of Cain the murderer, their men were like stallions neighing after the women, and the women would (likewise pursue) after the men shamelessly, and they were fornicating and wantonly sinning, each with one another, openly and publicly. Two or three men would cohabit with one woman, the old were more depraved than the young, fathers upon their daughters and sons upon their mothers. Children did not recognize their parents nor did parents their children, and they dallied with pagan deities. The sound of their cries and their laughter reached the top of the holy mountain.
Then when the progeny of Seth heard the noise, one hundred of their males assembled together for the purpose of descending the mountain unto the progeny of Cain the accursed. Yared adjured them by the blood of Abel not to descend from the holy mountain, but they would not hearken to his words, and so they descended. Then when they had descended, they beheld the daughters of Cain the accursed, (and saw that) they were beautiful, being naked (and going about) without shame, and they became consumed with desire (for them). So too the daughters of Cain beheld them, (seeing) that they were handsome men, giant-like (jababira), and so they acted as if they were wild animals, and polluted their bodies. Hence the sons of Seth came to ruin through the harlotry of the daughters of Cain.
And the daughters of Cain the accursed gave birth to giants (jababira) from their union with the sons of Seth. In the Torah it says that they were ‘sons of God,’ having the name beney ’elohim. When they saw the beautiful daughters of Cain, they descended to them, and it is from them that the giants (jababira) came to be. But one errs and misunderstands (if) he says that ‘angels’ descended to ‘mortal women.’ Instead, it is the sons of Seth who descend from the holy mountain to the daughters of Cain the accursed. For it was on account of their saintliness (chastity?) and dwelling-place upon the holy mountain that the sons of Seth were called banu ’elohim; that is, ‘sons of God.’ And when some say that angels descended unto mortal women, they are in error; for the substance of angels is a simple substance, and sexual plurality (i.e., gender distinction) is not part of their nature, while human beings have a complex substance, (and) sexual plurality forms part of their nature, as so too with all the animals. If angels could have sexual intercourse, there would not be left one virgin from among all human women that they would not defile.
And when those sons of Seth who had descended from the mountain to the daughters of Cain the accursed wished to return to the holy mountain, the stone of the mountain became as fire (to their touch), and so it was not possible for them to return to the mountain. After this more fellow kinsmen began to descend from the holy mountain to the daughters of Cain the accursed.