Number of rak‘ahs in Duha prayer

Praise
be to Allah.

The
minimum number that has been reported in the case of Duha prayer is two
rak‘ahs. Muslim (720) narrated from the hadeeth of Abu Dharr (may Allah be
pleased with him) that the Prophet (blessings and peace of Allah be upon
him) said: “…and two rak’ahs offered in the forenoon (Duha) will suffice for
that.” 

Al-Bukhaari (1981) and Muslim (721) narrated from the hadeeth of Abu
Hurayrah (may Allah be pleased with him) that he said: My close friend
(blessings and peace of Allah be upon him) advised me to do three things: to
fast three days of every month, to pray two rak‘ahs of Duha, and to pray
Witr before going to sleep. 

With regard to the maximum number, there is no text that defines that, but
it is proven that the Prophet (blessings and peace of Allah be upon him)
prayed Duha with four

rak‘ahs, and with more than that, and with eight rak‘ahs, as on the day of
the conquest of Makkah. 

Muslim
(719) narrated that Mu‘aadhah (may Allah have mercy on her) asked ‘Aa’ishah
(may Allah be pleased with her): How many (rak’ahs) did the Messenger of
Allah (blessings and peace of Allah be upon him) pray in Duha? She said:
Four rak‘ahs, and however many more he wanted. 

Muslim
(336) narrated that Umm Haani’ (may Allah be pleased with her) said: The
Messenger of Allah (blessings and peace of Allah be upon him) got up to do
ghusl, and Faatimah screened him. Then he took his garment and wrapped it
around himself, then he prayed eight rak’ahs of Duha prayer. 

It
says in al-Mawsoo‘ah al-Fiqhiyyah (27/225): There is no difference of
opinion among the fuqaha’ who say that Duha prayer is mustahabb with regard
to the minimum number of rak‘ahs being two. Abu Dharr (may Allah be pleased
with him) narrated that the Prophet (blessings and peace of Allah be upon
him) said: “…and two rak’ahs offered in the forenoon (Duha) will suffice for
that.” So the minimum for Duha prayer is two rak‘ahs, because of this
report.

However they differed concerning the maximum. 

The
Maalikis and Hanbalis are of the view that the maximum for Duha prayer is
eight rak‘ahs, because of the report narrated by Umm Haani’ (may Allah be
pleased with her), according to which the Prophet (blessings and peace of
Allah be upon him) entered her house on the day of the conquests of Makkah
and prayed eight rak‘ahs. (She said:) and I never saw any prayer that was
more brief than it, although he bowed and prostrated perfectly. 

The
Hanafis and Shaafa‘is – according to the more correct view – and Ahmad,
according to a report narrated from him, are of the view that the maximum
for Duha prayer is twelve rak‘ahs, because of a report narrated by
at-Tirmidhi and an-Nasaa’i, with an isnaad in which there is some weakness,
according to which the Prophet (blessings and peace of Allah be upon him)
said: “Whoever prays Duha with twelve rak‘ahs, Allah will build for him a
palace of gold in Paradise.”

End
quote. 

The
correct view is that there is no specific maximum number for Duha prayer;
rather a person may pray as many rak‘ahs as he wants, so long as this prayer
is done two rak‘ahs by two. 

Shaykh
Ibn Baaz (may Allah have mercy on him) said: 

The
minimum – for Duha – is two rak‘ahs, and there is no maximum number. But the
Prophet (blessings and peace of Allah be upon him) prayed two and four
rak‘ahs, and on the day of the conquest of Makkah he prayed Duha with eight
rak‘ahs, on the day on which Allah granted him the conquest of Makkah. So
this matter is broad in scope. Whether a person prays eight or ten or twelve
rak‘ahs, or more than that, or less, there is nothing wrong with it, because
the Prophet (blessings and peace of Allah be upon him) said: “The (Sunnah)
prayers of the night and day are two (rak‘ahs) by two.” The Sunnah is to
pray two by two, saying the salaam after each two rak‘ahs.

End
quote from Majmoo‘ Fataawa Ibn Baaz, 11/389 

Shaykh
Ibn ‘Uthaymeen (may Allah have mercy on him) said: 

The
correct view is that there is no maximum limit, because ‘Aa’ishah (may Allah
be pleased with her) said: The Prophet (blessings and peace of Allah be upon
him) used to pray Duha with four rak‘ahs, and however many more he wanted.
Narrated by Muslim. And she did not mention any limit. If a person prayed
forty rak‘ahs, for example, between the time when the sun reaches the height
of a spear and just before the sun reaches its zenith, all of that would be
included under the heading of Duha prayer.

End
quote from ash-Sharh al-Mumti‘, 4/85 

Note:
naafil (supererogatory) prayers are to be offered two rak‘ahs by two,
whether that naafil prayer is offered by night or by day. See the answer to
question no. 45268 

And
Allah knows best.