The Way in Which the Prophet Prescribed Voluntary Fasts
1. Three days every month:
Abu Zharr al-Ghifari reported:
"The Messenger of Allah ordered us to fast for three days of every month--that is, on the days of the full moon (the 13th, 14th, and 15th of the islamic month).And he said: It is like fasting the whole year.'"
[an-Nasai and Ibn Hibban]
2. Mondays and Thursdays:
Abu Hurairah reported that the most the Prophet would fast would be Monday and Thursday. He was asked about that and he said:
"The actions are presented on every Monday and Thursday. Allah forgives every Muslim or every believer, except for those who are boycotting each other. He says [about them]: Leave them.'"[Ahmad]
3. The Maximum Fast of Every Second Day:
Narrated Abdullah bin Amr bin Al-As:
The Prophet said to me:
"You fast daily all the year and pray every night all the night?"I replied in the affirmative. The Prophet said,
"If you keep on doing this, your eyes will become weak and your body will get tired. He who fasts all the year is as he who did not fast at all. The fasting of three days (a month) will be equal to the tasting of the whole year."I replied,
"I have the power for more than this."The Prophet said,
"Then fast like the fasting of David who used to fast on alternate days and would never flee from the battle field, on meeting the enemy.[Bukhari]
Special Times for Fasting
1. The month of al-Muharram:
Abu Hurairah reported that he (the Messenger of Allah) was asked as to which prayer was most excellent after the prescribed prayer, and which fast was most excellent after the month of Ramadan. He said:
"Prayer offered in the middle of the night and the most excellent fast after (fasting) in the month of Ramadan is the fast in Allahs month al-Muharram. "[Muslim]
2. The day of Ashura: Ibn Abbas reported:
"The Prophet came to Madinah and found the Jews fasting on the day of Ashura. He said to them:
'What is this fast?[Bukhari and Muslim]
They said: A great day. Allah saved Moses and the tribes of Israel from their enemies on this day and therefore, Moses fasted on this day.
The Prophet said: We have more of a right to Moses than you, so he fasted on that day also and ordered the people to fast on that day."
3. Six days of Shawwal:
Abu Ayyub al-An sari reported that the Prophet, upon whom be peace, said:
"Whoever fasts during the month of Ramadan and then follows it with six days of Shawwal will be [rewarded] as if he had fasted the entire year." [Related by "the group,"except for al-Bukhari and an Nasai]
4. Other specific days:
There is also evidence as Hafsah reported:
"There are five things that the Prophet never abandoned:[Ahmad and an-Nasai]
fasting the day of Ashura,
fasting the [first] ten [days of Dhul-Hijjah] ,
fasting three days of every month
and praying two Rakah before the dawn prayer."
The Prophet (peace be upon him) would fast the first ten days of the month of Dhul-Hijjah. (The day of Arafat is the 9th day of Dhul-Hijjah)
May Allah, grant us all the strength of Iman and Taqwa to perform as many voluntary deeds as we can for His sake, Ameen.