Come in under the shadow of this red rock (idea) by swinger4life

This line also alludes to another of Eliot's poems, "The Death of Saint Narcissus" which reads

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.

I have also heard this is a Biblical allusion to Isaiah 32:1-2 where the coming of the Messiah will be "as the shadow of a great rock in a weary land."

The hyacinth girl	The Waste Land	Philosophus Stone Against the Cult of Terror!	I can think of worse things than to die like a dog
What the Thunder Said	And the things you can't remember tell the things you can't forget	Too cool for school, too dumb to get a job	I will show you fear in a handful of dust
Cartoonish super-villainy	Preludes	Under Contruction	eyeshadow
Where to go for help with punctuation	You can teach people truth, but it's harder to teach them to cope with truth.	the flecks of smoke and sparks don't conjure you back from the ground or heaven	Throwing A Rock into the Water
Where the stars do drown	First Day Cover	Between a scream and a sigh: Conflicting duties in Joy Kogawa's Obasan	Street Moses ( nothingventured )
A Tale in the Desert	Rock collection	Shadow of a Doubt	Come with us