Folks, I Contacted the Universal House of Justice about this question. What they said is they can't find anything specific, but they suggest it is probably the Long Healing Prayer. Here is the text of the response that I received:
28 September 2008
Transmitted by email: firstname.lastname@example.org
Mr. Robert Yoder
Dear Bahá’í Friend,
Your email message of 11 August 2008, regarding a statement by Shoghi Effendi about
the significance of the daily obligatory prayers, the Healing Prayer and the Tablet of A-mad,
was received by the Office of Public Information at the Bahá’í World Centre through the Web
and forwarded to our Department for response.
As to the Healing Prayer to which the Guardian refers, it is probably the one known as
the Long Healing Prayer, but nothing specific about this has been located at this time.
Concerning the Long Healing Prayer, you may find of interest the following excerpt from
a memorandum dated 7 August 1997 written by the Research Department at the instruction of
the Universal House of Justice:
While no direct reference to the power of the Long Healing Prayer has been
located in the Writings translated into English, it is interesting to observe that there
is a passage near the end of this prayer which seems to suggest its potential. We
And again do I beseech Thee, by these most beauteous names, by these
most noble and sublime attributes, and by Thy most Exalted
Remembrance, and by Thy pure and spotless Beauty, and by Thy
hidden Light in the most hidden pavilion, and by Thy Name, cloaked
with the garment of affliction every morn and eve, to protect the bearer
of this blessed Tablet, and whoso reciteth it, and whoso cometh upon it,
and whoso passeth around the house wherein it is. Heal Thou, then, by
it every sick, diseased and poor one, from every tribulation and
distress, from every loathsome affliction and sorrow, and guide Thou
by it whosoever desireth to enter upon the paths of Thy guidance and
the ways of Thy forgiveness and grace.
In addition, as Ms. …’s friend is no doubt aware, in His Memorials of the
Faithful , ‘Abdu’l-Bahá relates a story about the dramatic effect which the recitation
of the Long Healing Prayer had on Mírzá Ja‘far-i-Yazdí. This story can also be
found in Hand of the Cause ‘Alí-Akbar Furútan’s Stories of Bahá’u’lláh.
The House of Justice was sorry to learn of your wife’s struggles with cancer, and you may
be assured of its prayers in the Holy Shrines on her behalf, that she may be surrounded by the
loving protection and tender mercies of the Blessed Beauty.
With loving Bahá’í greetings,
Department of the Secretariat