Ayyub (RadiyAllahu Anhu) relates that the Messenger of Allah salallahu ‘alayhi wa sallam said:
“Whoever fasts Ramadan and follows it with six days from Shawwal, it is as if they fasted the entire year”
[Muslim, Abu Dawud, Tirmidhi, and Ibn Majah; Ahmad transmitted it from Jabir, Muntaqa].
Thawban (RadiyAllahu Anhu) relates that the Messenger of Allah salallahu ‘alayhi wa sallam said:
“Whoever fasts Ramadan, and then six days after Eid, it is [like fasting] an entire year. Whoever does a good deed shall have ten times its reward”
[Ibn Majah, Muntaqa].
(36*10=360)
1. Based on this, the majority of the fuqaha, including the Hanafi, Shafi’i, and Hanbali school, have held that it is recommended to fast six days of the month of Shawwal.
[Radd al-Muhtar; Mughni al-Muhtaj Shah al-Minhaj; Kashshaf al-Qina’].
2. It is permitted to fast these six days separately throughout the month, or consecutively after Eid al-Fitr.
[ibid.].
3. It is prohibitively disliked (makruh tahriman) and sinful to fast on Eid day itself.
[Radd al-Muhtar].
4. The Shafi’is and Hanbalis state that it is superior to make the six fasts consecutive [Minhaj, GhayataI Muntaha]. Khatib al-Shirbini explains the reasoning as being, “In order to hasten to do the good and because of the problems inevitable in delaying,” such as becoming lazy and not actually fulfilling this sunnah in the end, though he points out that the sunnah is fulfilled by both consecutive and non-consecutive fasting of six days in Shawwal [Mughni al-Muhtaj]. The later, Hanafi scholars differed as to which is better, fasting the’ six days consecutively or (non-consecutively, though neither is disliked and both fulfill the sunnah [Radd al-Muhtar]. However, it would be agreed that those who fear not fulfilling the recommendation due to laziness, forgetfulness or other excuses, should hasten to fast the six days consecutively immediately after Eid al-Fitr.
5. The reward is akin to having fasted obligatory fasts the entire year days, according to Buhuti, Shirbini, and others.
Abu Hurayrah (RadiyAllahu Anhu) said that the Prophet salallahu ‘alayhi wa sallam said:
“The strong believer is better and more beloved to Allah than the weak believer, though there is good in both. Be avid for that which benefits you. Rely on Allah and do not deem yourself incapable…”
[Muslim 4816, Ibn Majah 76, Ahmad 8436]. Imam Nawawi (may Allah be pleased with him) explained that the ‘strength’ in this hadith refer to,” One’s determination and ability in matter of the next life”
[Sharh Sahih Muslim].
And Allah alone gives success. [ref.: Ibn Abidin, Radd al-Muhtar’ala al-Durr al-Mukhtar 2.125 Bulaq ed. Khatib al-Shirbini, Mughni al-Minhaj Sharh al-Minhaj 2.184-185; Buhuti Kashshaf al-Qina’ 2.237-238]