The garden is supposed in Gen 2:8 to be “eastward in Eden”; what does that mean?

As “eastward” is relative to something, and since the book is held to be written by Moses, presumably Eden is east of the Promised Land, although this is not altogether clear. “East” of the Promised Land would include, consistently with other uses of the word in the Bible, due north and northeast, along the Fertile Crescent; invasions “from the east” were actually, at least in their last hundred miles, from due north. As to where Eden was, the answer, as commentators say, can only be inferred from the proffered details. Mostly, we must look at the rivers, on which, see below.

What is the Tree of Life, first introduced in Gen 2:9, and why is there one? Is it symbolic?

It was the fruit of this tree that made Adam immortal when he was in the Garden; by being specifically cut off from the tree, he was made mortal. As Gen 3:22 has it, God evicted Adam “lest he put forth his hand, and take also of the tree of life, and eat, and live for ever”. The tree makes a reappearance in Revelation, which has the tree at the center of the New Jerusalem, “bearing twelve kinds of fruit…and the leaves of the tree were for the healing of the nations.” (Rev. 22:2) The tree will straddle a new river, like that of Eden. Evidently the symbolism is very rich: Jesus is called the “true vine” (John 15:1) and “the way, the truth, and the life” (John 14:6). Proverbs says that wisdom itself is metaphorically a tree of life (Prov. 3:18), as well as things that flow from wisdom, including desire fulfilled (Prov. 13:12), a healing tongue (Prov. 15:4), and the fruit of the righteous (Prov. 11:30). By placing this holy and life-sustaining tree in the Garden, God was specially blessing the innocent and sinless Adam; and it is only after being washed of their sins that man can again eat of this tree. Hence it seems to be a symbol for every sort of blessing one might have in a paradisiacal state in which one might dwell in God’s presence.

Based on Gen 2:10-14, what can we tell about the location of the land of Eden?

We know the Hiddekel, or Tigris, as well as the Euphrates. The headwaters of these two rivers came from a single river that went out of Eden—out of the surrounding land, not out of the garden—and then split into “four heads” at the garden, because “from thence it was parted” (this detail is not to be overlooked). There is no such headwater river in modern Turkey. The other rivers are unknown. Since the Gihon “compasseth the whole land of Ethiopia,” it is often guessed to be the Nile, but this is not geographically consistent with the other facts given, unless the land was somehow very different indeed at that time. The word is actually not Ethiopia but Cush, כּֽוּשׁ, and that might stand for some actually unknown land in ancient Anatolia—contrary to the Septuagint, which does render the word Αἰθιοπίας, Ethiopia. Similarly, the meaning of the river Pison or “the whole land of Havilah” is unknown. But perhaps the best guess is that Eden was in modern-day Turkey, near ancient Cappadocia. Going about naked there today would be a bit chilly, but God would no doubt have taken care of that issue. After all, beyond all this, we must bear in mind that all of this takes place, according to the text, before the Flood. If a worldwide flood actually took place, it would probably have changed the surface of the earth enormously. Not just river courses, but mountain ranges and entire continents might have changed.

Are there other interesting mentions of Eden in the rest of the Bible?

Perhaps the most interesting is at Ezek. 28:13, which says the wicked king of Tyre was at one time

…in Eden the garden of God;
every precious stone was thy covering,
the sardius [ruby], topaz, and the diamond…

And further, “Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.” (Ezek. 28:15) In this way, the story of the Fall was recapitulated but in connection to “the prince of Tyrus” who said, “I am a God, I sit in the seat of God” (Ezek. 28:2)—a passage often thought to have a second meaning referring to the tempter in the Garden, usually understood to mean Satan.

Is the command at Gen 2:16-17—not to eat of the tree—the first in the Bible?

It is the first command given to a named, individual man. God created in Gen 1 through words of command, and arguably, “Be fruitful, and multiply” at Gen 1:28 was a command, although it might also, or instead, be a blessing, and anyway it was given to animals as well as the whole race of man. In any event, this is the first instance in which a particular man is given a command that he might rebel against.

What is the Tree of the Knowledge of Good and Evil, first introduced in Gen 2:9, and why is eating of it forbidden, even deadly (2:17)?

This is a profound and important question. One might go on.—Why is it not called the Tree of Death, since it is so closely contrasted with the Tree of Life? And what is wrong with knowledge, even knowledge of good and evil? Are we forbidden to study ethics? Does Proverbs not enjoin us to seek wisdom? Does Jesus not instruct us to be “wise as serpents, and harmless as doves” (Matt. 10:16)?—The way to deal with all such questions is to produce the right theory regarding the symbolic meaning of the tree. It was the only forbidden thing on earth at the time. By making it available, God was, it seems, testing man—here, to be carefully distinguished from tempting man—who failed the test. Thereby God acknowledged man’s free will. To come to the point, then, eating from the tree represented not merely breaking God’s first commandment; it represented our freely substituting our own judgment, and our pretensions to be able to judge what is good and evil for ourselves. So the tree brought death, true, but it brought it by respecting man’s free choice. Since Adam and Eve were initially sinless and innocent, like children, eating from the tree was very like the first act of childhood rebellion against authority. In response, God repaid the rebellion by removing his protection and caretaking. Fruit of this tree resulted in a kind of knowledge of good and evil in the intimate sense of directly experience of deciding what is good and evil, as well as being made to suffer the consequences of rebelliously taking him out from under God’s tutelage. Of course, knowledge and wisdom are good, studying ethics is fine, and we ought to seek wisdom in order the better to do God’s will. What was punished was not seeking after that sort of wisdom, but instead open rebellion against a loving God that, as a side-effect, led to direct experience, and so knowledge, of evil. Indeed, as we will see, Adam and Eve should not have listened to the serpent, and if they were as wise as him, they would not have been taken in. But more about this later.

But surely the events starting at Gen 2:16, in chapters 2 and 3—command, temptation, fall, and expulsion—are puzzling because God must have known that man would fall, no? So why test him?

God commands us to be righteous, but there is no significance to a command given to robots that lack the ability to refuse. It seems to me that God preferred beings capable of refusing to mere robots; that is, surely, part of being made in God’s image. But indeed he did know what would happen in advance (many other examples of God’s foreknowledge are in the Bible; we need not marshal examples). So it must have been his will, not precisely that man would fail the test, but that failing the test was a necessary step in the movement toward the ultimate creation he wished to make. In short, one must imagine that God will prefer things better in the New Jerusalem, with wiser sinners made pure through the blood of the Lamb, than with Adam in the Garden.

If it is true that God will prefer things better in the New Jerusalem—with wiser sinners made pure through the blood of the Lamb—then really, what sense does it make to say it was knowledge that was forbidden (in Gen 2:17)?

But it is not that holy wisdom that was forbidden. Moreover, eating of the tree hardly gave Adam and Eve that knowledge. It only made them lose their innocence; it made them aware of their self-chosen responsibility for themselves and rebellion from God. But more on that later.