Thank you for your response About the Son of God, I can see that you understand that the Word is more complex in meaning than it seems. And that is because God does not reveal His hidden goods for the casual reader, but to those who hunger for truth.
I am not actually looking as to why all this happened for I already know why the Bible tells us why.
I wasn't trying to explain why it all happened, but only why the tree was placed there, and I did so to indicate what the tree's purpose was, and hence -- what the tree was expected to produce.
I am really looking for one word that explains what kind of fruit did the tree of life produce that would be able to give us eternal life?
Hmm....
In terms of biblical history, I think it likely that the tree was supposed to produce dates -- as in palm dates.
The cherubim whom are placed around the garden to prevent enterance, are the same creatures who carry God's mobile (but often invisible) throne in Ezekiel, and again mentioned in Revelation; so that the Chrubim are understood not only to be guards of the garden of eden, but also as creatures carrying the mystical garden around for God to gaze down into. Cherubim are also are the "horses" (so to speak) of God's eternal chariot ; although the cherubim, and the seraphim who stand on top of them -- have human hands with which to actually carry the throne of God and are not mere animals.
Moses himself made a copy of this heavenly throne and a walled in area (paradiso/paradise/garden), as a "model" of the cosmos (order), of the world -- the model is called the ark of the covenant and tent of meeting (trysting place), AKA the mercy seat ; and it too was carried by human hands and placed in a walled in area. Hence, the place to look for images when deciding what the tree is -- I would infer as being best found in the artwork Moses commanded the Israelites to make of God's paradise and throne which the Cherubim carried , eg: the model is known as the temple of Jerusalem from Solomon's time onward.
The only tree woven into the tapestries of the temple according to the books of Moses -- around the holy of holies -- is the palm tree. There is quite a bit of biblical and historical Jewish extra-biblical evidence, that the straight and tall date-palm tree is associated with god-liness and goodness. Eg; for one example, the prophetess Deborah, is known to have issued judgments (as a judge/ruler) under one. Judges 4:4-5. And the symbolism is important -- date palms are both straight and very tall, reaching up toward heaven.
Also, Note, the final (or near final) textual form of Genesis was compiled in Babylon, during the captivity; wherein the stories that Moses told orally were arranged in the particular order needed to help the Jews prepare for the coming of the messiah; So the oral traditions of the Jews of that time were arranged in ways which served as an apologetic against the heresies of the Babylonians in order to help the Jews keep their religious identity while in captivity. Biblical texts often bring up points in a specific order, and with
subtle differences from the Babylonian own versions of religious texts in order to give reasons that the Babylonans ought to let the Jews live (Babylon was Abraham's homeland, for one thing, they were 'brothers' like Cain and Abel) and that they ought not fight for their common ancestor Abraham, and his cosmologies (which also meant their laws, for Genesis is a book of laws) had ambiguities which made certain practices illegal to both peoples. I won't attempt to explain the symbolism of the tree of life as the Babylonians understood it, as history has mostly forgotten it -- but I will point out, that even the Babylonians depicted the tree of Life as having Palm fronds.
As an aside:
I do not disagree that 'trees' often symbolize rulers within scripture, as you pointed out -- although I don't think the scripture you quoted shows anything about rulers. (Mark 8:24, though in the Greek I think if I remember right that it says, dendrites -- rather than xylum, so it's really more like 'branches' walking than trees....) So -- I would just like to mention that I think you would be better off citing examples in the old testament about the 'cedars' of Lebanon where the prophecies and images would help people in a bible study forum grasp the point more clearly.
In ancient cultures, including Babylon, the tree of life was often alternated with an image of their king or ruler in the same place as the tree. So -- yes, there is good evidence -- both inside and outside of the bible -- that rulers are seen as analogous to trees.