4:16 Then Cain went away from the presence of the LORD, and dwelt in the land of Nod, east of Eden. 17 Cain knew his wife, and she conceived and bore Enoch; and he built a city, and called the name of the city after the name of his son, Enoch. 18 To Enoch was born Irad; and Irad was the father of Me-hu’ja-el, and Me-hu’ja-el the father of Me-thu’sha-el, and Me-thu’sha-el the father of Lamech.
“Cain knew his wife…’ Even in the 4th Century the Patristic writers puzzled over from whence Cain’s wife could have come since the scriptures are silent about their origin. Some thought God simply populated the earth with other people, some felt she must have been a daughter of Eve and that incest was justified at that time in order to secure the continuation of the human race. The text seems to be following only a particular people, keeping the others outside the purview of the story. It’s not denying that there are other humans created by God, but they are clearly secondary characters in relationship to those the Bible focuses on.
“…he built a city..” The notion of Cain building a city seems to contradict the curse that God placed on him in verse 14 where is made into a wanderer. Such contradictions may indicate different traditions have been blended into the final text (so Source Theory would argue) or that the text is not meant to be read with an inflexible literalism.
The first mention of a city occurs in the lineage of Cain. “Civilization” is not presented in the best of light in this passage. The “city” is seen as founded by sinful and violent men. There is no mention of God in the city. The fact that a “city” would be built suggests there are many more people in existence than our Genesis story is accounting for. Cities can only exist if people (the farmers) have learned how to produce more food than they need for their own survival. City life assumes the residents can purchase needed food or otherwise everyone would live on their own farms to sustain life. City life implies a certain level of social development – life developed beyond that of nomadic tribesmen. The story doesn’t tell us what constitutes a “city” at this point, so we have no way of knowing what building a city requires; it probably implies, however rudimentary, some architecture, engineering and building skills, and also the tools and simple machines to do the job. In Sirach 38 we read the following ancient ideas about what it takes to establish a city: “So too is every craftsman and master workman who labors by night as well as by day; those who cut the signets of seals, each is diligent in making a great variety; he sets his heart on painting a lifelike image, and he is careful to finish his work. So too is the smith sitting by the anvil, intent upon his handiwork in iron; the breath of the fire melts his flesh, and he wastes away in the heat of the furnace; he inclines his ear to the sound of the hammer, and his eyes are on the pattern of the object. He sets his heart on finishing his handiwork, and he is careful to complete its decoration. So too is the potter sitting at his work and turning the wheel with his feet; he is always deeply concerned over his work, and all his output is by number. He moulds the clay with his arm and makes it pliable with his feet; he sets his heart to finish the glazing, and he is careful to clean the furnace. All these rely upon their hands, and each is skilful in his own work. Without them a city cannot be established, and men can neither sojourn nor live there. … But they keep stable the fabric of the world, and their prayer is in the practice of their trade” (38:27-33).
Unusual in the genealogy of Cain is that his death and that of his descendents is not recorded, nor are their ages listed. Did the inspired author of Genesis want their memories forgotten as soon as is possible?
The names of Cain’s descendents are going to be paralleled almost exactly in the family tree of Seth (Genesis 5:15-25). The names Enoch, Me-hu’ja-el, Me-thu’sha-el, and Lamech all have corresponding names in the genealogy of Seth in the same order of birth. The significance of the repeated list is not known. One theory of scholars is that the list of names is unquestionably ancient but through time oral tradition which carried the memory of these forefathers became unclear as to whether it was Cain or Seth’s lineage. So both possibilities were recorded in Scripture. We see perhaps a similar issue in the New Testament in which the names in the ancestry of Christ in Luke 3:23-34 and Matthew 1:3-16 do no completely coincide.