What was the significance of the Keruvim, and the revolving sword, that Hashem placed in front of Gan Eden?
Rashi #1: To frighten Adam from ever re-entering the Garden again. 1
Seforno: Hashem placed them there before Adam left Gan Eden, 2 so that he should not pick fruit from the Eitz ha'Chayim on his way out. 3
Targum Yonasan: Hashem blocked Adam's access to the fruit of the Eitz ha'Chayim, since it symbolized the everlasting reward for the study of Torah and the performing of Mitzvos, which, following his sin, would only fall due after death. In the event that he did not deserve it, he would be sent to Gehinom.
Da'as Zekenim and Rosh: The revolving sword is Gehinom - it switches from hot to cold and from cold to hot, for the Resha'im.
See Rashi, in Pasuk 24, regarding where they were placed.
This implies that, once Adam left the Gan Eden, the guards were no longer necessary,
This is problematic however, since the Eitz ha'Chayim was in the middle of the Garden (as stated above [Bereishis 2:9]), and the guards were placed in front of (or to the east side of) the Garden?
From what was Adam expelled (va'Yegaresh)? (The previous verse (3:23) already said that Adam was "sent out"?)
Rosh #1: He was expelled from the gates (of Gan Eden).
Rosh #2: He was expelled due to afflictions. Also, due to him, the Mikdash would be destroyed, as in the verse, "va'Yagres be'Chatzatz Shinai" (Eichah 3:16). 1
Hashem confronted Adam with the word "Ayekah" (3:9); Hashem would later confront Bnei Yisrael with the same word, "Eichah" (Midrash Raba 19:9; also see Kinah 14 of Tish'ah b'Av). (CS)
What were the Keruvim?
Rashi They were angels of destruction.
Rosh: They were two angels in the form of oxen that plowed in Gan Eden. 1
Ba'al ha'Turim: The acronym of the word "Lishmor es Derech Eitz ha'Chayim" is Lilin (female demons), Sheidin, Mazikin, Ruchin - different kinds of demons
In Aramaic, plowing is "Kerava".
What is the "Lahat ha'Cherev ha'Mis'hapeches"?
Rashi: It is the blade of a rotating sword. 1
Rosh: It is Gehinom, which switches from hot to cold and vice-versa, for Resha'im.
Gur Aryeh: Rashi writes: "The rotating sword - which had sharpness (Lahat)." Lahat is not an independent object, but an adjective describing the sword.
Why is the rotating sword described as "Lahat"?
Gur Aryeh (to Shemos 7:22): The blade is polished and sharpened, and appears to be on fire. (Fire is another meaning of the word Lahat, e.g. Malachi 3:19.) 1
Also see Rashi to Shemos 7:11 and to Shemos 7:22; where "Lahat" has the connotation of incantation or sorcery.
What is Derech Etz ha'Chayim? (Did anyone make a path to it?!)
Vayikra Rabah (9:3): Derech Eretz existed 26 generations before the Torah. 1 "Derech" refers to Derech Eretz, and afterwards is Etz ha'Chayim, i.e. Torah.
Chochmah u'Musar (Vol. 2, p. 444): What is Derech Eretz, which preceded the Torah? It is to make the senses and powers of one's soul subservient to intellect.
QUESTIONS ON RASHI
Rashi writes: "'East of Gan Eden (mi'Kedem l'Gan)' - east of the garden, on the outside." What is Rashi explaining?
Gur Aryeh: "Mi'Kedem" means on the east side. I might have thought that they were stationed in the eastern portion of the garden itself, but then the verse should have said, 'Mi'Kedem b'Gan.'
Rashi writes: "On the east side of Gan Eden." Why specifically there?
Maharal (Gevuros Hashem Ch. 70, p. 322): The word "Kedem" means 'east,' but it also means 'beginning.' One who is doing Teshuvah must return to the original sinless state in which he was created. 1
Also see Rashi to 4:16; refer to 4:16:1.1:1.
