Genesis 12:10-13

At that time, a severe famine struck the land of Canaan, forcing Abram to travel down to Egypt and live there as a foreigner. When he drew near to Egypt, he said to his wife Sarai, “Look, I’m worried because I know that you are a beautiful, gorgeous woman. When the Egyptian men take one look at you, they will say, ‘She is his wife.’ Then they will kill me in order to have you. Just tell them you are my sister so that they will treat me well for your sake and spare my life.”