Noah was a pretty good genetic choke point for us all.
That said, there are two camps: (1) she was his half-sister (different mothers) or (2)Sarai was the daughter of Iscah and Abraham’s deceased brother Haran (and thus his niece).
The express language is unclear. The oral tradition takes the position that’s she was his niece.
Icky, either way, I agree.
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But we know that the “oral tradition” began after the return to the land. Guesswork most likely, since Moses got his version directly from Yehova at Sinai.
I sure wouldn’t mary my sister (if I had one).