It is not prescribed to do a single prostration for the sake of du’aa’

Some people, when they want to offer du'aa' after praying, prostrate
and offer du'aa' whilst prostrating. Is this prostration Sunnah?.
Praise be to Allaah.
Islam does not prescribe drawing close to Allaah bymeans of
prostration unless the prostration is in the prayer (salaah) or for a
specific reason, such as prostration of forgetfulness (sujood al-sahw,
if a mistake is made in the prayer), or prostration of recitation
(sujood al-tilaawah, required when reading certain verses of the
Qur'aan), or the prostration of gratitude (sujood al-shukr).
As for prostration for the sake of du'aa', there is nothing in
sharee'ah to indicate that it is permissible or mustahabb. Rather what
is proven from the Prophet (blessings and peace of Allaah be upon him)
in many mutawaatir hadeeths is that he used to raise his hands in
du'aa', and he encouragedothers to do so. He said: "Your Lord, may He
be blessed and exalted, is characterized by modesty and generosity,
and He is so Kind to His slave that, ifHis slave raises his hands to
Him, He does not let him take them back empty." Narrated by Abu Dawood
(1488); classed as saheeh by al-Albaani inSaheeh Abi Dawood.
So prostrating for the sake of du'aa' is an innovation, because the
Prophet (blessings and peace of Allaah be upon him) did not do it, and
because it is forsaking theSunnah that the Prophet (blessings and
peace of Allaah be upon him) encouraged, which is raising the hands in
du'aa'.
These scholars denouncedthis single prostration andforbade it. It was
mentioned by Abu Shaamah (may Allaah have mercy on him) in his book
al-Baa'ith 'ala Inkaaral-Bida' wa'l-Hawaadith (p. 62, 63) and he said:
Imam al-Haramayn Abu'l-Ma'aali said: The author ofal-Taqreeb mentioned
from some of his companions that if a man submits to Allaah and
prostrates for no reason, he may do that, and I have not seen this
except with him. My Shaykh regarded that as makrooh, and objected
strongly to anyone who did that. He said: this is my view.
Abu Haamid al-Ghazali said: Shaykh Abu Muhammad (may Allaah have mercy
on him) objected strongly to the one who did that, and thisis the
correct view. He said in Kitaab al-Nadhr: No one was of the view that
prostration on its own becomes obligatory if one makes a vow to do
that, because it is not an act of worship for which there is a reason,
such as recitation (i.e., prostration of recitation).
Imam al-Haramayn said: My Shaykh was of the definite opinion that
prostration on its own does not become obligatory if one makes a vow
to do that, even though the reciter of the Qur'aan may prostrate, but
prostration on its ownfor no reason is not an actof worship according
to the correct view.
The author of al-Tatimmah said: Some people have the habit of
prostrating after they finish the prayer and saying du'aa' whilst
doingso. He said: We know of no basis for this prostration and it was
notnarrated from the Messenger of Allaah (blessings and peace of
Allaah be upon him) or from his Companions. It is better to offer
du'aa' during the prayer, because of the reports that have been
narrated concerning that. And Allaah knows best.
I (Abu Shaamah) say: The fact that prostration is an act of worship
within prayer does not necessarily mean that it isan act of worship
outside of prayer, like bowing. Al-Faqeeh Abu Muhammad said: Islam
does not say that one may draw close to Allaah by doing a single
prostration for which there is no reason.