So God sanctioned incest...what an interesting belief system you have. Incest was perfectly all right until God gave Moses the Ten Comandments...funny I don’t recall “Thou shalt not sleep with your siblings, children, parents, et al” anywhere in the Ten Commandments. Must have been in the five that Mel Brooks dropped as he was coming down the mountain.
Huh?
Just go into the alternate universe where perhaps the Bible is true for a second.
Adam and Eve are the first people. It was “incest” for quite a while.
Interesting question, though I did think it through historically — I need to do a concordance search on the Hebrew. Interesting problem. Leviticus is where it is mentioned without cracking open a Bible. Chapter 18. Infamous text that Paul also refers to with Peter in the New Testament.
Then get a Bible and read it.