To me it sounds symbolic not because of the words used but the setting. A few points i have been wondering:
1. The garden of Eden and therefore the tree of life was on earth somewhere. When Adam and Eve were banished, an angel with a flaming sword was placed to prevent them from accessing this tree.
The question is- what happened to this tree? did it die like other physical trees? if it dies then it can not be the tree of life anymore can it?
2. The bible starts with story of this tree of life and also ends with this tree in Revelation again:
Rev 22:
1 Then the angel showed me the river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb
2down the middle of the great street of the city. On each side of the river stood the tree of life, bearing twelve crops of fruit, yielding its fruit every month. And the leaves of the tree are for the healing of the nations.
3No longer will there be any curse. The throne of God and of the Lamb will be in the city, and his servants will serve him.
4They will see his face, and his name will be on their foreheads.
5There will be no more night. They will not need the light of a lamp or the light of the sun, for the Lord God will give them light. And they will reign for ever and ever.
In between Genesis and Revelation, there has been heavy symbolism of 'a tree that doesn't bear fruit being cut down'.
Could we be the tree? and being a tree that doesn't bear fruit is the heart that doesn't know God?
I'm not sure but in Revelation, we see symbolism of this tree come out clearly.