Cross reference
Genesis 20:12
12 Moreover she is indeed my sister, the daughter of my father, but not the daughter of my mother; and she became my wife.
Genesis 11:29
29 Abram and Nahor took wives. The name of Abram's wife was Sarai, and the name of Nahor's wife, Milcah, the daughter of Haran who was also the father of Iscah.
Genesis 12:13
13 Please say that you are my sister, that it may be well with me for your sake, and that my soul may live because of you."
1 Thessalonians 5:22
22 Abstain from every form of evil.