"In Islamic literature, the soul, symbolically associated with water and blood, is generally represented by green birds (green finches) or, more precisely, the souls after death dwell in the gizzards of birds which fly around the throne of God (a very ancient idea)." Louis Massignon, on The Idea of Spirit in Islam. Mason's poem, "Finch," is a reflection, as in a mirror, of this ancient Islamic myth (Young-Mason).
FINCH
My soul is like a small green bird
Which flies around my father's chair.
His chair is vacant now, at least
It seems no one is seated there.
It has a song I cannot hear
Which someone else may one day sing
Should he return, though no one has
Reported anything.
It isn't physical, I'm told;
Some say it's spiritual and very high;
And yet, the finch's sound is like
A human cry.