This excerpt is taken from the book of Fadhilat al-Shaykh Mubashir Ahmad Rabbani, may Allah have mercy on him, Ahkam wa Masail Ramadan.
Fasting in any month other than Ramadan is not permissible:.
Question:.
I have seen that people continuously fast in Rajab and Sha'ban and then also fast in Ramadan. They do not abandon fasting during this period. Is there any hadith regarding this? If so, what are the words of that hadith?
Fatwa:.
There is no authentic hadith that states that the Prophet (peace be upon him) observed fasting for the entire month of Rajab or the entire month of Sha'ban. Nor is there any evidence of such practice from any companion (may Allah be pleased with him). In fact, it is not established that the Prophet (peace be upon him) fasted all the days of any month other than Ramadan. In an authentic hadith narrated by Sayyida Aisha (may Allah be pleased with her), it is mentioned that:
كان رسول الله صلى الله عليه وسلم يصوم حتى نقول لا يفطر ويفطر حتى نقول لا يصوم فما رأيت رسول الله صتكمل صيام شهر إلا رمضان وما رأيته أكثر صياما منه فى شعبان
The Messenger of Allah (peace be upon him) used to fast continuously until we would say that he would never break his fast, and he would remain without fasting continuously until we would say that he would never fast, and I did not see the Messenger of Allah (peace be upon him) fasting for an entire month in any month other than Ramadan.
Reference: (Bukhari, Book of Fasting, Chapter on Fasting in Ramadan: 1969, Muslim, Book of Fasting, Chapter on the Fasting of the Prophet (peace be upon him): 1152/175)
This hadith has been narrated by Bukhari and Muslim (may Allah have mercy on them).
Our master Abdullah bin Abbas (may Allah be pleased with him) states that:
ما صام النبى صلى الله عليه وسلم شهرا كاملا قط غير رمضان وكان يصوم حتى يقول القائل لا والله لا يفطر، ويفطر حتى يقول القائل لا والله لا يصوم
"The Prophet (peace be upon him) never fasted an entire month except for Ramadan, and he used to fast continuously until people would say, 'By Allah! He will not break his fast this month,' and he would continue fasting until people would say, 'By Allah! He will not fast this month.'"
Reference: (Bukhari, Book of Fasting, Chapter on What is Mentioned About the Fasting of the Prophet (peace be upon him) and His Breaking of Fast: 1971, Muslim, Book of Fasting, Chapter on the Fasting of the Prophet (peace be upon him): 1157)
Therefore, fasting the entire month of Rajab or the entire month of Sha'ban as voluntary fasts is contrary to the Sunnah and practice of the Messenger of Allah (peace be upon him). Thus, it is an innovation, and the Prophet (peace be upon him) stated:
من أحدث فى أمرنا هذا ما ليس منه فهو رد
"Whoever introduces something into this religion of ours that is not part of it, it will be rejected."
Reference: (Bukhari, Book of Reconciliation, Chapter on If They Agree on an Unjust Reconciliation: 2297, Muslim, Book of Judgments, Chapter on Annulment of Pre-Islamic Judgments: 1718)
