The original
Thou hast made me endless, such is thy pleasure. This frail vessel thou emptiest again and again, and fillest it ever with fresh life.
This little flute of a reed thou hast carried over hills and dales, and hast breathed through it melodies eternally new.
At the immortal touch of thy hands my little heart loses its limits in joy and gives birth to utterance ineffable.
Thy infinite gifts come to me only on these very small hands of mine. Ages pass, and still thou pourest, and still there is room to fill.
The edited version
You have made me endless; such is your pleasure.
This frail vessel you empty again and again, and fill it again and again with fresh life.
This little reed of a flute you have carried over hill and valley, and have breathed through it melodies eternally new.
At the immortal touch of your hands, my little heart loses its limits in joy.
Your infinite gifts you place in these very small hands of mine.
Ages pass and still you pour and still there is room to fill.
The reasoning
Step 1 is to remove the clunky “thees” and “thous,” and verbs ending with “est” (“thou fillest” for “you fill”).
In the second sentence, we encounter the repeated action of emptying and filling a vessel. The use of “ever” stilted; I remove it and replace it with the same “again and again” that appears earlier. Now we have a bit of parallel construction, and we emphasize the cyclical nature of the emptying and filling of the vessel.
I replace “hills and dales” with “hill and valley” because the cadence is smoother.
“Utterance ineffable”: This phrase grates on me. “Ineffable” means “unspeakable,” or “unutterable,” as in the ineffable beauty of a sunrise, or the ineffable vastness of the cosmos. So what is an “utterance ineffable”? An “utterance unutterable”? I don’t know how to replace it; I don’t know whether it’s worth replacing. What if we delete it? I think I shall.
“Thy infinite gifts…”: The middle of the sentence (“…come to me only on…”) is clunky and, in being drawn out with too many words, sound scraping and obsequious.
“…room to fill”: I considered “room for more,” but perhaps that rhyme is too facile.
As for the line breaks, I am not yet certain that they matter at all.
Thoughts? Let me know.