Where Did Cain Get His Wife?
A common question is, where did Cain get his wife? Humanity started with just two people, so there had to be a lot of close intermarriage, and at least one instance of brother-sister marriage. Isn't this a moral problem? No, it was not prohibited until the law was given to Moses... because at that point it was no longer genetically healthy to marry a close relative. Before then, there were no problems. Abraham married his half-sister and it was okay.
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