‘Oh, God, make me a hollow reed, from which
the pith of self hath been blown so that
I may become as a clear channel through which
Thy Love may flow to others.’
A commentary on the uncertain origins of this prayer is here – http://bahai-library.com/uhj_hollow_reed_prayers
One of the most interesting comments is;
COMMENTARY ON THE ELEVENTH CHAPTER OF THE REVELATION OF ST. JOHN
This reed is a Perfect Man Who is likened to a reed, and the manner of its likeness is this: when the interior of a reed is empty and free from all matter, it will produce beautiful melodies; and as the sound and melodies do not come from the reed, but from the flute player who blows upon it, so the sanctified heart of that blessed Being is free and emptied from all save God, pure and exempt from the attachments of all human conditions, and is the companion of the Divine Spirit.
Whatever He utters is not from Himself, but from the real flute player, and it is a divine inspiration. – Some Answered Questions, by `Abdu’l-Bahá, p. 45:
Another interesting comment is the possibility that the prayer may be in Rumi’s ‘Mathnavi’.