תּלמוד אויף בראשית 20:16

R Elazar further said in the name of R. Hanina: Let not the curse of an ordinary man be held lightly in your eyes, because Avimelech cursed Sarah, saying, “Behold he is for you a covering of the eyes” (Genesis 20:16) and this was fulfilled in her seed, [as it says], “And it came to pass that when Isaac was old his eyes were dim” (Genesis 27:1).

But was that the cause? Did not R. Yitzchak say: Let not the curse of an ordinary person ever seem light in your eyes, for Avimelech cursed Sarah, and it was fulfilled in her seed, as it says, “Behold he is for you a covering [kesut] of the eyes” (Genesis 20:16). Read not “kesut” but “kesiyath” [blinding]?