Genesis 26:1-7

1 Now there was a famine in the land, besides the former famine that had occurred in the days of Abraham. And Isaac went to Gerar, to King Abimelech of the Philistines.
2 The Lord appeared to Isaac and said, "Do not go down to Egypt; settle in the land that I shall show you.
3 Reside in this land as an alien, and I will be with you, and will bless you; for to you and to your descendants I will give all these lands, and I will fulfill the oath that I swore to your father Abraham.
4 I will make your offspring as numerous as the stars of heaven, and will give to your offspring all these lands; and all the nations of the earth shall gain blessing for themselves through your offspring,
5 because Abraham obeyed my voice and kept my charge, my commandments, my statutes, and my laws."
6 So Isaac settled in Gerar.
7 When the men of the place asked him about his wife, he said, "She is my sister"; for he was afraid to say, "My wife," thinking, "or else the men of the place might kill me for the sake of Rebekah, because she is attractive in appearance."