Egyptians cannot eat together with the Ivrim, "Ki To'evah Hi." What is this?
Targum Onkelos and Targum Yonasan: Because the Ivrim ate the animals that the Egyptians worshipped.
Rashbam: Because the Egyptians were conceited and looked down on the Ivrim, whom they considered inferior. Likewise, they despised shepherds who raise Tzon, which they considered disgusting. 1 Da'as Zekenim (to 46:34) says so as well.
Moshe said, "If we will sacrifice To'avas Mitzrayim in front of their eyes, will they not stone us?!" (Shemos 8:22). He did not say 'they will kill us' (Da'as Zekenim). Rashbam - Rather, they will throw earth amidst contempt. (Why should we be concerned for contempt of pagans?! Perhaps this was a mere pretext why we must leave - PF)
Why did Yosef not sit with his brothers?
Seforno: So that the brothers should not realize that he was an Ivri.
Why does the verse need to say that Egyptians cannot eat with Ivrim?
Ha'amek Davar: This explains why the Egyptians did not eat with Yosef's brothers. Do not say that it explains why they did not eat with Yosef. They revered him! Rather, they did not eat with him lest he be belittled in their eyes, or lest they need to be too careful [lest they upset him].
QUESTIONS ON RASHI
Rashi writes: "'It was an abomination [to the Egyptians]' - ... Onkelos gives a reason for this" [i.e. the Ivrim would eat sheep, which the Egyptians worshiped]. Why did the Egyptians deify the sheep?
Maharal (Gevuros Hashem Ch. 37, p. 140): The Egyptians were Chomer, which comes first in relation to Tzurah. They worshipped the lamb, which is the first of the constellations. 1
In Maharal's terminology, Chomer is potential, and Tzurah is the actualization of that potential; thus, Chomer precedes Tzurah. The Egyptians were base physicality, with no inclination to grow or fulfill any goal. They therefore worshipped the first instance of Chomer. (EK) Also refer to 39:1:1.6:1, and the note there.
