" Needless to say, all the poet really sees is a tree in a meadow; he is not thinking of a legendary Yggdrasill that would concentrate the entire cosmos, uniting heaven and earth, within itself. But the imagination of round being follows its own law: since, as the poet says, the walnut tree is "proudly rounded," it can feast upon "heaven's great dome." The world is round around the round being.

And from verse to verse, the poem grows, increases its being. The tree is alive, reflective, straining toward God.

Dieu lui va apparaitre
Or, pour qu'il soit sur
Il developpe en rond son etre
Et lui tend des bras murs.

Arbre qui peut-etre
Pense au-dedans.
Arbre qui se domine
Se donnant lentement
La forme qui elimine
Les hasards du vent!

(One day it will see God
And so, to be sure,
It develops its being in roundness
And holds out ripe arms to Him.

Tree that perhaps
Thinks innerly
Tree that dominates self
Slowly giving itself
The form that eliminates
Hazards of wind! "

― Gaston Bachelard , The Poetics of Space