מלאכים (angels) acting as intermediates
for the Tefilos ,is mentioned in the Gemoro (Shabbos 12b).
Tefilos directed to the מלאכים* started in the times of the
Gaonim. We find in Selichos, Pizmonim & Piyutim where we
daven directly to the מלאכים.
Kabbalists had a practice of forcing an oath on
the מלאכים. ( משביעין את המלאכים ).
Hashem gives permission to the מלאכים to do as they
are commanded (by humans) even if the recipients are
not worthy and have no zechusim for the favour. (Levush)
There used to be a Minhag for Chazanim to force an
oath on the מלאכים.
The Chazanim were concerned, an עין הרע will cause them to lose
their voice during Davening.
The Chazanim had a Nusach they said, before saying המלך.(Yomim Noroim)
בשם שמעי' -------(שמות של מלאכים)---- אני פלוני בן פלוני משביע אני עליכם (
שתסייעו לי שאתפלל היום בקול רם ונעים וערב ואל יחר גרוני ואל ילאה רוחי וכוחי
(In the name of the Malochim --- I Ploni the son of Ploni, place a Shevuah
on you (Malochim) that you will help me to Daven today with a voice
that is loud, pleasant and sweet, and my throat shouldn’t anger (cough)
and my spirit and strength shouldn’t tire.)
The Levush (O.Ch.584) was against this השבעה (oath). He claims it
is wrong to force Hashem to accept your Tefillos**. The acceptance of
Tefillos is dependant on the כוונת הלב,and you may not force it.
The second issue the Levush had against it, was, Hefsek, The Nusach was
said after ברוך שאמר.(before Hamelech)
The Levush suggest to eliminate it altogether and if not possible, then it
should be said beforeברוך שאמר.
*Many Poskim(Maharal, Vilna Gaon< Chasam Sofer etc.)
were against it, but weren’t successful,in stopping it.
** loss of voice would be a sign of non acceptance of Tefilos