Genesis 12:10-13

Then a famine came to the land. Abram went down to Egypt to live; it was a hard famine. As he drew near to Egypt, he said to his wife, Sarai, “Look. We both know that you’re a beautiful woman. When the Egyptians see you they’re going to say, ‘Aha! That’s his wife!’ and kill me. But they’ll let you live. Do me a favor: tell them you’re my sister. Because of you, they’ll welcome me and let me live.”