פּירוש אויף בראשית 12:17

'וינגע ה' וגו AND THE LORD PLAGUED PHARAOH etc. — He was smitten with the disease of Raathon for which marital relations are harmful.

Sarai, Avram’s wife. She cried out that she was Avram’s wife but Pharaoh refused to listen.

וינגע ה' את פרעה, “Hashem afflicted Pharaoh with a painful plague;” the reason why the Torah offers no further details about the nature of this plague, as opposed to when Avimelech was struck with impotence and the women in his country were afflicted in their birth canals, is because shortly after the episode with Avimelech the Torah reported that Sarah conceived and became pregnant (Genesis 21,1). Had the Torah not spelled out that Avimelech had become totally impotent, people might have attributed Sarah’s pregnancy to her having stayed in Avimelech’s Palace. The episode with Pharaoh had occurred perhaps a s long as 20 years earlier, so that no one could have fabricated such a story. To the question why Pharaoh was punished, seeing that Avram had deceived him by saying that she was his sister, as we know from the Torah quoting him, Sarai had described herself as Avram’s wife even if he had not said so. This is the meaning of the words: על דבר שרי אשת ברם “on account of what Sarai, Avram’s wife had said.” Pharaoh had ignored her. Gentiles do not have to be warned not to violate the commandments they have accepted to observe, as we pointed out in connection with Genesis 20,5. (The second Avimelech and Rivkah)