Genesis 4:17-26
Cain has a Child
17 Cain lay with his wife, and she became pregnant and gave birth to Enoch. Cain was then building a city, and he named it after his son Enoch. 18 To Enoch was born Irad, and Irad was the father of Mehujael, and Mehujael was the father of Methushael, and Methushael was the father of Lamech.
19 Lamech married two women, one named Adah and the other Zillah. 20 Adah gave birth to Jabal; he was the father of those who live in tents and raise livestock. 21 His brother's name was Jubal; he was the father of all who play the harp and flute. 22 Zillah also had a son, Tubal-Cain, who forged all kinds of tools out of bronze and iron. Tubal-Cain's sister was Naamah.
23 Lamech said to his wives,
"Adah and Zillah, listen to me;
wives of Lamech, hear my words.
I have killed a man for wounding me,
a young man for injuring me.
24 If Cain is avenged seven times,
then Lamech seventy-seven times."
25 Adam lay with his wife again, and she gave birth to a son and named him Seth, saying, "God has granted me another child in place of Abel, since Cain killed him." 26 Seth also had a son, and he named him Enosh.
At that time men began to call on the name of the LORD.
We are not told much about Cain's wife...She just appears...Where did she come from?...
We are really not told much about Abel...We do not know how old Abel is when Cain murders him or how many children Abel had...We do not know how much time has taken place when Cain leaves the east part of Eden for Nod... We are not told how many children Adam and Eve have...
When God created Adam and Eve interracial marriage was unavoidable...Only later in Leviticus 18-20 is marriage and sexual relations with close relatives prohibited...Remember, Abraham would marry his half sister Sarah...With so few people in the near East (the world), you did not meet a lot of new people...The first form of traveling would have been walking or running, so the world was not spread out immediately...
The Bible does not tell us everything in every situation...The Bible is like connecting the dots...Not all are connected...I think Jesus will connect all the dots when we meet Him in heaven...
The most likely scenario is that Cain is older than his wife...She is either a niece or a sister of his...At the very least she is a close relative, depending on how old he is...
We also learn from the text here that Cain's grandchildren Jubal and Tubal-Cain were talented...Jubal can play both the harp and flute...Tubal-Cain forged all kinds of tools out of bronze and iron...So we know some of of earliest ancestors are musicians and tool makers...They found time for both work and play...