Abu Hurayrah (may Allah be pleased with him) said,
“The Prophet (sallallahu alahi wassalam) advised me to do three (things): fast three days out of every month, pray two rak’ahs in the forenoon and to perform the witr prayer before I sleep (at night).” (Saheeh Al-Bukhaari)
Abu Dharr narrated that the Prophet (sallallahu alaihe wassallam) said, “Every morning there is on the bones and joints of any of you a charitable act. Every saying of 'SubhaanAllah' is a charitable act; every saying of 'Alhumdullilah' is a charitiable act and every saying of ‘Laa illaaha illallah' is a charitable act; every saying ‘Allahu akbar’ is a charitable act; ordering good is a chartiable act; eradicating evil is a charitable act. To fulfill that charity, it is sufficient to pray two rakat of the forenoon.” (Muslim 364)
Narrated Anas (may Allah be pleased with him) Allah's Messenger (sallallahu alaihe wassllam) said, "Whoever prays twelve Rakats (units) of Dhuhaa, Allaah will build a castle for him in Paradise." (At-Tirmidhi who graded it Gharib "unfamiliar, doubtful").
Number of Raka’ahs (Units of Prayer):
The minimum number of rak’ahs for the Forenoon prayer is two, based on the hadith just quoted and its maximum is eight. Umm Haani' narrated that on the day of the Conquest of Makkah, the Messenger of Allah (sallallahu alaihe wassallam) bathed in her house and then prayed eight rak’ahs. (Bukhari, Muslim)
The Difference Between Ishraaq and Dhuhaa
Ishraaq (“ishrak”) prayer is Dhuhaa (“chast”) prayer offered at the beginning of its time. These are not two different prayers. It is called Ishraaq because it is done immediately after sunrise (shurooq) when the sun has risen to a certain height.
The Best Time to Perform the Forenoon Prayer:
The time of Dhuhaa prayer is from the time when the sun has risen to a certain height, until just before the time for Dhuhr prayer.
The scholars defined this as being when one quarter of the day has passed, i.e., halfway between sunrise and Dhuhr prayer. (See al-Majmoo’ by al-Nawawi, 4/36; al-Mawsoo’ah al-Fiqhiyyah, 27/224 .)
So all of this period is the time for Dhuhaa prayer.
It is better to pray it after the sun’s heat has become intense, because the Prophet (peace and blessings of Allaah be upon him) said: “It is preferable to offer Dhuhaa prayer when the sun’s heat has become so intense that even the young of the camels feel it.” (Narrated by Muslim, 748)
Zayd ibn Arqam said that the Prophet (sallallahu alaihe wassllam) went out to the people of Quba and they were praying the Forenoon prayer. He said, “The prayer of the penitent is when the weaned camels feel the heat of the sun,” during the forenoon. (Muslim 368)
This Hadeeth also indicates that the best time of Dhuhaa prayer is just before noon.
Narrated 'Aa'ishah (may Allah be pleased with her):
Allaah's Messenger (sallallahu alaihe wassllam) entered my house and prayed eight Rakats (units) of Dhuhaa prayer. (Ibn Hibban in his Sahih)
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