Salat Duha is a prized prayer and whoever wishes to earn the reward should perform it while there is no harm upon the ones who does not pray it.
Merit of the Duha (Forenoon) Prayer
Duha prayer is a sunnah prayer, it is from 2 to 8 rakah
1139. Abu Hurairah (May Allah be pleased with him) reported: My Khalil (the Messenger of Allah (PBUH)) directed me to fast three days of each month, and to observe two Rak`ah Duha (optional prayer) at forenoon, and to perform the Witr prayer before going to bed. [Al-Bukhari and Muslim].
This Hadith also highlights the importance of Duha and Witr prayer, and proves the merit of giving counsel persuasion and inducement for virtuous deeds.
1140. Abu Dharr (May Allah be pleased with him)reported: The Prophet (PBUH) said, “In the morning, charity is due on every joint bone of the body of everyone of you. Every utterance of Allah’s Glorification (i.e., saying Subhan Allah) is an act of charity, and every utterance of His Praise (i.e., saying Al-hamdu lillah) is an act of charity and every utterance of declaration of His Greatness (i.e., saying La ilaha illAllah) is an act of charity; and enjoining M`aruf (good) is an act of charity, and forbidding Munkar (evil) is an act of charity, and two Rak`ah Duha prayers which one performs in the forenoon is equal to all this (in reward).”[Muslim].
1141. `Aishah (May Allah be pleased with her) reported: The Messenger of Allah (PBUH) used to perform four Rak`ah of Duha prayer (at the forenoon) and would add to them whatever Allah wished.[Muslim].
1142. Umm Hani, daughter of Abu Talib (May Allah be pleased with her) reported: I went to the Messenger of Allah (PBUH) on the day of the conquest of Makkah. He was taking a bath at that time. When he finished the bath, he performed eight Rak`ah (of optional) prayers. This was during the Duha (forenoon).[Al-Bukhari and Muslim].
Time for the Duha (Forenoon Optional) Prayer
1143. Zaid bin Arqam (May Allah be pleased with him) reported: I saw some people performing Duha (prayers) in the early forenoon and warned them (saying): These people must know that performing Salat a little later is better. The Messenger of Allah (PBUH) said, “The Salat of the penitent is to be observed when the young ones of camels feel the heat of the sun (i.e., when it becomes very hot).”[Muslim].
Commentary: The best time for Duha prayer is when the hoofs of the animals begin to burn and they feel troubled with the heat of the sun.
Praying the Duha prayer with faith and expectation of the reward promised for it, or out of the desire to pray it with sincerity in it, without any showing-off or wanting to heard or seen, or to store up a reward with Allah.
hadith ‘A human being has 360 joints for each of which he must give alms-Sadaqah. The people asked: Who is capable of doing this? He replied (saw): It may be mucus in the mosque which you bury, and something which you remove from the road; but if you do not find such, two rak’ahs in the forenoon (meaning salat ad-Duha) will be sufficient for you.’
Everyone has been created with 360 joints. Whoever mentions Allah’s greatness (says Allahu Akbar), praises Allah, extols Allah, and seeks forgiveness from Allah and removes stones from the path of the people, enjoins what is good and forbids evil to the amount of those 360 joints, he walks on that Day (of Judgment) having distanced himself from the Fire.”
The 2 rak’ahs of salat ad-Duha is a complete sadaqah on behalf of the 360 joints of the body.
The surah of Quran to read ideally with Salat Ad-Duha;
1st rakah Surah Duha(Check this article for the details of Surah Dhuha.) and 2nd rakah Surah Inshirah, if you don’t know these, then recite the surah you do know.