Genesis 26:6

3 And sojourn in it, and I will be with thee, and will bless thee: for to thee and to thy seed I will give all these countries, to fulfil the oath which I swore to Abraham thy father.

4 And I will multiply thy seed like the stars of heaven: and I will give to thy posterity all these countries: and in thy seed shall all the nations of the earth be blessed.

5 Because Abraham obeyed my voice, and kept my precepts and commandments, and observed my ceremonies and laws.

6 So Isaac abode in Gerara.

7 And when he was asked by the men of that place, concerning his wife, he answered: She is my sister: for he was afraid to confess that she was his wife, thinking lest perhaps they would kill him because of her beauty.

8 And when very many days were passed, and he abode there, Abimelech, king of the Palestines, looking out through a window, saw him playing with Rebecca, his wife.

9 And calling for him, he said: It is evident she is thy wife: why didst thou feign her to be thy sister? He answered: I feared lest I should die for her sake.