The analogy of the Torah as the Tree of Life is particularly striking when we examine the respective focal points of the Garden of Eden and the Temple. Just as the Tree of Life stood at the conceptual center of the Garden of Eden, the tablets of testimony, symbolizing the Torah as a whole, rest at the focal point of the Temple in the Holy of Holies. (Exodus 26:33). Thus the motif of a life-giving source at the center of Eden is preserved in the form of the tablets of testimony in the Temple.

In this light, the Synagogue practice of returning the Torah to the Ark after its public reading takes on new light.
  Taken from “The Temple, It’s Symbolism and Meaning, then and now” by Joshua Berman.