It is a sunnah that, if one must choose between permissible
alternatives, one may pray two non-obligatory rak'at, even if they are
of the regular sunnah prayers or a prayer for entering the mosque, and
so on, during any time of the day or night, and to recite therein
whatever one wishes of the Qur'an after reciting al-Fatihah. Then one
praises Allah and sends salutations to the Prophet sallallahu alehi
wasallam and recites the following supplication which has been recorded
by al-Bukhari in Jabir's narration: "The Prophet sallallahu alehi
wasallam would teach us al-istikhara for all of our affairs as he would
teach us a surah from the Qur'an. He said: 'If one of you is
deliberating over an act, he should pray two non-obligatory rak'at and
say:
"O Allah, I consult You as You are All-Knowing and I appeal to You
to give me power as You are Omnipotent, I ask You for Your great favor,
for You have power and I do not, and You know all of the hidden matters
. O Allah ! If you know that this matter (then he should mention it) is
good for me in my religion, my livelihood, and for my life in the
Hereafter, (or he said: 'for my present and future life,') then make it
(easy) for me. And if you know that this matter is not good for me in
my religion, my livelihood and my life in the Hereafter, (or he said:
'for my present and future life,') then keep it away from me and take
me away from it and choose what is good for me wherever it is and
please me with it."
There is nothing authentic concerning something specific that is to
be recited in the prayer nor is there any authentic report concerning
how many times one should repeat it.
An-Nawawi holds that "after performing the istikharah, a person must
do what he is wholeheartedly inclined to do and feels good about doing
and should not insist on doing what he had desired to do before making
the istikharah. And if his feelings change, he should leave what he had
intended to do, otherwise he is not completely leaving the choice to
Allah, and would not be honest in seeking aid from Allah's power and
knowledge. Sincerity in seeking Allah's choice, means that one should
completely leave what he himself had desired or determined."