The names that appear in this short genealogy recall those provided by the author of Genesis 5 (see 1-18). It is impossible to say who these persons were. Instead, we have to pay attention to the author’s intention. In chapter 4, Enoch is a son of Cain, while in Genesis 5 he is a descendant of Set. In Genesis 5, Cain is not even named – although the other names are quite similar to those of chapter 4 – unless consider Kenan (5:9) as an alternative form of the name Cain. Perhaps a single genealogical text has been used and arranged in two different ways on the basis of the author’s different intentions.
Perhaps in the fourth chapter, the author pointed out that the seventh of Adam’s descent – through Cain – was the evil Lamech, while in chapter 5 the seventh of Adam’s descent – through Set – was instead the just Enoch. Again the verse seems to contradict the curse that God launched against Cain (see Gen 4:12). It is impossibile for a fugitive and vagabond man to have descendants. This is possibile only for a man who had a permanent home with a wife and descendants who came from the same and recognized progenitor.
Moreover, genealogy is composed of seven elements and seven is the number of completeness, totality and perfection. Therefore the family of Cain, with his descendants, acquires a further positive accent, in clear contradiction with the condition in which Cain was forced to live.
Gen 4:1-16 and 4:17-26 are different texts, with different intentions and authors. Genesis 1-11, unlike Genesis 12-50, is a set of texts that are very different from each other and joined together by different thematic threads, the main one being the degeneration of humanity after the transgression of Adam and Eve (Gen 3).