Is it permissible to offer an unlimited number of Rak`ahs in the Sunnah (supererogatory) Salah,
for example a hundred, a thousand or two thousands Rak`ahs? In his book Fiqh Al-Sunnah, Al-Sayed Sabiq cited evidence for this. Is there a difference between the meaning of Nafilahs (supererogatory acts) and Sunnahs (commendable acts) of worship?
A person may offer Nafilahs as many as they want. There is no limit in the Shari`ah for this as far as we know unless there is other evidence from the Shari`ah that specifies Nafilahs such as in the Sunnah of Zhuhr (Noon), Maghrib (Sunset), `Isha' (Night) and Fajr (Dawn) Prayers or the Sunnah after the Jumu`ah (Friday) Prayer. In these prayers Allah's Messenger (peace be upon him) specified a certain number of Rak`ahs, for example four Rak`ahs before Zhuhr and two Rak`ahs after it, two Rak`ahs after Maghrib, (Part No. 7; Page No. 220) two Rak`ahs after `Isha', two Rak`ahs before Fajr and two Rak`ahs after Jumu`ah at one's home. Also it is authentically reported from the Prophet (peace be upon him) that he enjoined the person who wanted to pray a Sunnah Salah after Jumu`ah to offer four Rak`ahs.With regards to the meaning of Nawafil and Sunan, the word Nawafil means supererogatory acts of worship while the word Sunan refers to all that is permissible yet not Wajib (obligatory) such as Salat-ul-Duha (Sunnah Prayer after sunrise) and other Sunnah prayers related to the five obligatory prayers as well as Witr Prayer. All these are Sunnah prayers. Some are more highly stressed than others. They are also called Nawafil.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.