9 So Abimelek summoned Isaac and said, “She is really your wife! Why did you say, ‘She is my sister’?” Isaac answered him, “Because I thought I might lose my life on account of her.”

Read Genesis 26:9 Using Other Translations

And Abimelech called Isaac, and said, Behold, of a surety she is thy wife: and how saidst thou, She is my sister? And Isaac said unto him, Because I said, Lest I die for her.
So Abimelech called Isaac and said, "Behold, she is your wife. How then could you say, 'She is my sister'?" Isaac said to him, "Because I thought, 'Lest I die because of her.'"
Immediately, Abimelech called for Isaac and exclaimed, “She is obviously your wife! Why did you say, ‘She is my sister’?” “Because I was afraid someone would kill me to get her from me,” Isaac replied.