Why does the Torah need to tell us that the trees in the garden were "pleasant to look at"?
Seforno: The happy feeling that results from seeing something that looks nice, arouses one's desire for more spirituality; as we find with the Navi Elisha, who asked the minstrel to play him music to prepare for prophecy (Melachim II 3:15). 1
This is synonymous with the concept of performing a Mitzvah with Simchah, which enhances the Mitzvah tremendously.
Why does the Torah insert the (otherwise superfluous) words "ve'Eitz ha'Chayim be'Soch ha'Gan"?
Rashi: To teach us that it was located exactly in the center of the garden (so that it would distribute life to all the trees equally).
Since Hashem did not specify the species of tree of the Etz ha'Chayim and the Etz ha'Da'as, how was Adam supposed to know which two trees He was referring to?
Ramban: Clearly, the term "in the middle of the garden" refers to a specific location (possibly its exact middle, 1 as is indeed implied by Onkelos ['bi'Metzi'us Ginsa']), from which Adam knew to which trees Hashem was referring.
How would eating the fruits of these trees bestow life, or knowledge?
Maharal (Chidushei Agados, Vol. 3, p. 104-105, to Bava Basra 74a): These were not corporeal fruits such as we have today. Nor was "eating" in Gan Eden in the physical sense. Rather, filling of a lack, or attaining perfection, is referred to as "eating." 1
See Gur Aryeh at length regarding the Livyasan (Gur Aryeh to 1:21). Refer to 1:21:2.3:2* .
What is the Tree of Life?
Maharal (Derech Chayim, beg. Intro.): The "Etz ha'Chayim" is the Torah. (a) Torah is compared to a tree, for it is implanted firmly, and emanates from Hashem. (b) "Etz ha'Chayim" is in plural, whereas man is called 'Chai', in the singular. Man receives life, and it can be taken away; whereas Torah is the essence of life, and never ceases. (c) The Torah bestows life upon those who study it, and it is called a tree, for through the Torah, man is firmly planted before Hashem. 1
Also see Maharal (Derech Chayim 3:15, p. 148); by eating from the Tree of life, man would be fortified in Torah and attain of all its secrets.
What sort of tree was the Tree of Knowledge?
Maharal (Derech Chayim 4:21, p. 204): There are a few opinions in Chazal. (a) A grapevine. The tree is described as of "good appearance" (3:6); this trait appeals to the Nefesh. (b) Wheat. It was "desirable for understanding" (ibid.); this appeals to the intellect (Sechel). (c) Fig. It was "good for food" (ibid.); this appealed to man's desire (Ta'avah). (d) Esrog, which in Aramaic means "desire" in general, including all of the aforementioned aspects. 1
What was the "Eitz ha'Da'as Tov v'Ra"?
Ramban: Before they ate from the Tree of Knowledge, Adam and Chavah did what they had to do - such as having children - without any ulterior motives (such as love, hatred or desire), in the same way as the rest of the limbs do what is correct, without deviating one iota from the task at hand. 1 However, the fruit of the Eitz ha'Da'as ... created in those who ate it the desire to choose between what is good and what is evil in all their actions. 2
Seforno: Eating the fruit instilled in Adam an interest in good and bad, causing him to choose what is pleasant, even though it is harmful; and to reject what is unpleasant, even though it is beneficial.
Moshav Zekenim: It is knowledge of marital relations. Immediately after eating, they were aware that they were naked!
Maharal #1 (Derech Chayim 3:15, p. 148): Man is capable of knowing both good and evil, for he was created b'Tzelem Elokim. 3 It would be more fitting for him to know only good, and not evil. Man, as a creation, should strive to cling to his Prime Cause (Hashem); this attachment is the ultimate good. However, Man was placed in the lower realms, distanced somewhat from Hashem. If Man turns away from his Source, towards sin, he opens himself up to know evil as well.
Maharal #2 (Nesivos Olam, Nesiv ha'Temimus Ch. 1, p. 206): Man was created to connect with Hashem, and be wholesome with Him; to serve Him without craftiness. The snake, in contrast, was "cunning" (3:1) and distant from Hashem. He enticed Adam and Chavah to know both good and evil; knowledge that was unnecessary for them.
This explains what the Torah writes later (2:25) that "Adam and Chavah were naked and were not ashamed", since they used all parts of their bodies in the service of Hashem; impersonally, just as they used their hands. Likewise, the Ramban explains, when they were intimate, it was without any feelings of desire.
Targum Onkelos and Targum Yonasan, who translate it as 'Whoever eats from it will know the distinction between good and bad,' seem to concur with the explanation of the Ramban.
Tzelem Elokim relates to man's power of Bechirah. Also see Maharal (Derech Chayim 4:2, p. 206).
Why did the Torah not reveal the name of the tree to Adam and Chavah (see Bereishis 3:3)?
Ramban: Hashem deliberately declined to tell them the nature of the tree 1 - maybe because it was something that was beyond their grasp. It was therefore something that they would have to discover on their own. 2
The Torah does in fact mention it in (2:17), the Ramban points out, but that is only so that we should know which tree it was. Refer to 2:17:1:1 .
It may also be because reasons for a prohibition tend to arouse interest, to make a person inquisitive, so Hashem issued a prohibition without giving any reasons.
Why does it say "from the ground"?
Rosh (from Rashi to Bereishis 2:5): The trees and the plants were already finished just below the ground, but they did not come out until Adam prayed for rain.
QUESTIONS ON RASHI
Rashi writes: "'He caused to sprout' - The Pasuk refers to the [aforementioned] garden." How does Rashi know this?
Gur Aryeh: The Torah's narrative is not currently referring to the plants of the rest of the world, but to the trees of Gan Eden specifically.
Rashi writes: "'In the midst of the garden' (b'Soch) - at its center." How does Rashi know this?
Gur Aryeh: All the trees were inside the garden; what then was the uniqueness of the Etz ha'Chayim? Rather, "b'Soch" means, "at the center."
Rashi writes: 'In the midst of the garden' - at its center." But another verse (3:3) implies that it was the Etz ha'Da'as that was "in the midst of the garden"?
Moshav Zekenim (citing Ba'al ha'Mikreh): Only one tree can be in the middle! It follows that the Etz ha'Chayim was also the Etz ha'Da'as. 1
Gur Aryeh: According to the Midrash, both the Etz ha'Chayim and Etz ha'Da'as shared one root, located at the garden's center.
But after they ate, Hashem expelled them, lest they eat from Etz ha'Chayim (3:22)! Perhaps eating the fruit gives Da'as, and eating the wood gives eternal life. Or, if one eats after he has Da'as, then it gives eternal life. (PF)
