The Sister Lie

Genesis 25 & 26

“When the men who lived [in Gerar] asked Isaac about his wife, Rebekah, he said, ‘She is my sister.’ He was afraid to say, ‘She is my wife.’ He thought, ‘They will kill me to get her, because she is so beautiful.’” Genesis‬ ‭26‬:‭7‬ ‭NLT‬‬

Really? Second time using the sister lie in the same family line? Are we supposed to believe like father, like son? Seems a little too convenient to me. I wonder: did Isaac think he could extort money from the king if somehow the lie came to light, benefiting monetarily from the deception like his father had? Feels like part of the story is conveniently left out in these chapters to place a positive slant on Isaac’s less than honest motives. What are your thoughts?