One question I have often wondered about is the marriages of Adam and Eve’s children. They must have married their siblings. Is this true?
I see nothing in scripture to suggest otherwise. With Adam and Eve being the only people having children, their offspring would have no one else to marry.
I think we project our modern views into the scriptures and feel like maybe certain things were wrong. But, if you put yourself in their place, it would seem perfectly normal, because that’s all there was at the time and there was no prior precedent.
In my view they were following the commandment as given to them to multiply and replenish the earth in the only way that was available.