Genesis 12:11-13

12:11 As he approached Egypt, he said to his wife Sarai, “Look, I know that you are a beautiful woman. 12:12 When the Egyptians see you they will say, ‘This is his wife.’ Then they will kill me but will keep you alive. 12:13 So tell them you are my sister so that it may go well for me because of you and my life will be spared on account of you.”