Gênesis 20

Gênesis 20:12

(Chapter 20, verse 12.) Truly my sister is from my father, but not from my mother. That is, her father is Aran, not her mother. But because it says in Hebrew: truly my sister is the daughter of my father, and not the daughter of my mother: and it sounds more likely that she should be called Abraham's sister, we say this in her defense, that at that time such marriages were not yet prohibited by law. — Hebrew Questions on Genesis