Genesis 20:1-3, 4-5, 11-13

Abraham traveled from there south to the Negev and settled down between Kadesh and Shur. While he was camping in Gerar, Abraham said of his wife Sarah, “She’s my sister.”

Now Abimelech had not yet slept with her, hadn’t so much as touched her. He said, “Master, would you kill an innocent man? Didn’t he tell me, ‘She’s my sister’? And didn’t she herself say, ‘He’s my brother’? I had no idea I was doing anything wrong when I did this.”

Abraham said, “I just assumed that there was no fear of God in this place and that they’d kill me to get my wife. Besides, the truth is that she is my half sister; she’s my father’s daughter but not my mother’s. When God sent me out as a wanderer from my father’s home, I told her, ‘Do me a favor; wherever we go, tell people that I’m your brother.’”