“A whole afternoon field inside me from one stem of reed.
The messenger comes running toward me, irritated:
Why be so hard to find?
Last night I asked the moon about the Moon, my one question
for the visible world, Where is God?

The moon says, I am dust stirred up
when he passed by.The sun, My face is pale yellow
from just now seeing him. Water: I slide on my head and face
like a snake, from a spell he said. Fire: His lightning,
I want to be that restless. Wind, why so light?
I would burn if I had a choice. Earth, quiet
and thoughtful? Inside me I have a garden
and an underground spring.
This world hurts my head with its answers, wine filling my hand, not my glass.
If I could wake completely, I would say without speaking
Why I’m ashamed of using words.”

-Mawlana Rumi

These are the main interpretations that form in my mind when I read the poem:

The narrator is looking for signs of the existence of God through the elements of the visible world (moon, earth, fire, wind, etc.)
While the elements’ reactions to witnessing God are phenomenal and cause some of them to step outside their normal characteristics (the wind desires to burn and the earth is usually quiet and thoughtful, but it announces the great energy it has within: “Inside me I have a garden and an underground spring”), none of these answers are adequate enough to fulfill the curiosity of the narrator, and thus the narrator has wine pouring into his hand but not into the glass with which he can drink and satiate his curiosity and understanding of God. The words uttered by the elements are not enough to describe the majesty and reality of God.
I think that the poem is also alluding that the narrator needs to look at the “invisible” world instead of the visible world to find these signs. If the narrator looks within his own self, he will find the answers that he is looking for, for the human being is the microcosm of the universe, and the only creation that can fully reflect the attributes of God through his polished heart. The wind, fire, earth, etc. all emanate qualities that already exist within the human. I also think that the “glass” mentioned in the end of the poem can be a symbol for the heart, and that the words uttered by the elements are beautiful, but not enough to fill his heart. In conclusion, while it is excellent to look for signs of God in the visible universe around us, it is also just as important to look within and contemplate His Reality in the invisible world, and also to understand that words are not sufficient enough to explain His Reality. And it is perhaps better understood through experience that is felt.

And God knows best.