The pasuk [Breishis 12/17] says וינגע ה' את פרעה נגעים גדולים ואת ביתו - Hashem afflicted Paroh with great "negaim" and his household [when he took Sarah].
This is a seemingly odd phraseology. It SHOULD say that Hashem afflicted Paroh and his household with great "negaim". Why do the words נגעים גדולים interrupt between Paroh and ביתו.
This gives credence to what Rashi Hakadosh says: במכת ראתן לקה שהתשמיש קשה לו. He was afflicted with a disease called "ra'ason" which makes the act of relations painful.
So these negaim "separated" between man and woman. That is why in the language of the pasuk it "separates" between the words Paroh and ביתו.
[The Holy Kojiklover Gaon Rav Aryeh Tzvi Frommer ztz"l page 301]
