Genesis 12:10-13
There was famine in the country, and Abram went down to Egypt to stay there for a time, since the famine in the country was severe. When he was about to enter Egypt, he said to his wife Sarai, 'Look, I know you are a beautiful woman. When the Egyptians see you they will say, "That is his wife," and they will kill me but leave you alive. Therefore please tell them you are my sister, so that they may treat me well because of you and spare my life out of regard for you.'