What are the great plagues to which the Pasuk refers?
Rashi #1: It is the plague of Ra'asan, which makes intimacy difficult.
Rashi #2 (in the initial print): It means that Hashem inflicted Par'oh with every kind of plague that He would ultimately bring upon man.
Why does the Torah use the expression, "'Al Devar," "on the word, of Sarai (Sarah)"?
Targum Onkelus, Targum Yonasan and Ramban: The phrase simply means "due to the matter of," i.e. because of what Par'oh did to Sarah (and Avraham
Gur Aryeh: Had the verse intended the first explanation, it should have written, "Al Odos Sarai."
What are the impllications of ve'es Beiso"?
Rashi #1, Seorno, Targum Onkelos and Targum Yonasan: It means the members of his household.
Rashi #2: It refers literally to the walls of his house, its pillars and his household utensils.
Seeing as it was only Pharaoh who sinned, why did Hashem punish the members of his household?
Seforno: In fact, it was only Par'oh himself who was stricken with "great plagues"; the members of his household suffered minor ones. This was so that the only person in the palace who did not suffer was Sarah, and they would know without doubt, that it was all due to Sarah
How did Pharaoh deduce that Sarah was a married woman?
Gur Aryeh: The verse implies that only Pharaoh himself received Ra'asan, while the rest of his household received other plagues. He realized that he was singled out in order to prevent him from being intimate with Sarah.
Why did Hashem strike Pharaoh? He was Shogeg (unaware [that she was married])! Additionally, we find that Hashem warned Avimelech before striking him (20: 3,7), yet He did not warn Pharaoh?
Moshav Zekenim: Initially Pharaoh was Shogeg, but later he was Meizid after Hashem told him that she was Avraham's wife. She herself would not tell, for Avraham commanded her not to.
Riva: Avimelech was also stricken; all of his openings were closed. There is no source to say that Pharaoh was stricken more.
QUESTIONS ON RASHI
Rashi writes: "Great afflictions (Nega'im) - Pharaoh was afflicted with Ra'asan, which made intimacy difficult." How do we know it refers to Ra'asan?
Gur Aryeh #1: Why was he afflicted with Nega'im, and not other Chola'im (illnesses)? It must have been to make relations difficult for him.
Gur Aryeh #2: The verse implies that only Pharaoh himself received the "great afflictions," while the rest of his household received other plagues. He must have been singled out in order to prevent him from being intimate with Sarah.