Genesis 4:17

17. Cain knew his wife See on Genesis 4:1. “The text assumes it as self-evident that she accompanied him in his exile; also that she was a daughter of Adam, and, consequently a sister of Cain. The marriage of brothers and sisters was inevitable in the case of the children of the first men, if the human race was actually to descend from a single pair, and may, therefore, be justified in the face of the Mosaic prohibition of such marriages, on the ground that the sons and daughters of Adam represented not merely the family, but the race, ( genus,) and that it was not till after the rise of several families that the bonds of fraternal and conjugal love became distinct from one another, and assumed fixed and mutually exclusive forms, the violation of which is sin.” Keil.

Enoch Meaning initiated, as if with this son, and the city called after his name, Cain was instituting a new order of things.

He builded Literally, he was building. He began to build the city, perhaps before Enoch was born, and he continued building it long after. “The word city is, of course, not to be interpreted by modern ideas; a village of rude huts, which was distinguished from the booths or tents of the nomads, would satisfy all the conditions of the text.” Speaker’s Com. And yet something more pretentious than mere huts may well be understood. Nor is it far-fetched and irrelevant to trace in this first city-building the earliest attempt to centralize worldly forces, and construct something like world-empire, one of the outward forms of the later Antichrist. For the “mystery of iniquity” was already working in this very line of Cain, “who was of that wicked one.” 1 John 3:12. The location of this city named Enoch is, like the land of Nod, unknown .