(Come in under the shadow of this red rock),
And I will show you something different from either

from T.S. Eliot – The Waste Land on Rap Genius

Meaning

Eliot frequently re-used/morphed parts of his other poems; in this case, these lines from the opening of “The Death of Saint Narcissus”:

Come under the shadow of this gray rock -
Come in under the shadow of this gray rock,
And I will show you something different from either
Your shadow sprawling over the sand at daybreak, or
Your shadow leaping behind the fire against the red rock:
I will show you his bloody cloth and limbs
And the gray shadow on his lips.

The parentheses are probably an experiment in iconicity, and denote shelter and isolation. The tree has grown impotent and died. What’s left for shelter is a lifeless rock.

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