Why did Bil'am mention the fact that Keil took Yisrael out of Egypt?
Rashi: He mentioned it to counter Balak's statement 1 "Hinei Am Yatza mi'Mitzrayim", as if they left Egypt of their own accord.
Da'as Zekenim (20), Hadar Zekenim (20): The One who took them out is strong. Eil is an expression of strength. 2
What is the meaning of "ke'So'afos Re'eim Lo"?
Rashi #1: It means that He took them out of Egypt 'according to the Power of His Loftiness' 1 .
Rashi #2: 'He took them out of Egypt flying on high'. 2
Rashi #3 (citing Gitin, 68b): 'He took them out of Egypt with the might of demons'. 3
Ramban (on Pasuk 21): Hashem's superior strength over all nations is comparable to a Re'em's 4 superior strength over all other animals.
Targum Onkelos and Targum Onkelos: 'He took them out of Egypt, power and loftiness (praise and might
Rashi: With connotations of a fortress, as in Iyov, 22:25. "Re'eim" literally, is a buffalo or kind of wild ox.
Rashi: A sign of power.
See Sifsei Chachamim.
Zevachim 113b: Rabah bar bar Chanah saw a newborn Re'em. It was 40 Parsa'os.. See 'The Living Torah, which cites many opinions as to the meaning of "Re'em".
Seforno: Since, when they left Egypt, Hashem intended them to expel the Cana'anim and to inherit their land without killing its inhabitants, as the Pasuk indicates in Tehilim, 80:9. See Seforno.