Question 8: There is a Salaah (Prayer) offered on the second and the fourth nights of Shawwaal during the supererogatory fasting of the six days of Shawwaal. It is called Salaat-ul-Tasaabeeh (Prayer of glorification). It is offered after ‘Ishaa’ (Night) Prayer and consists of four Rak‘ahs (units of Prayer), with Tasleem (salutation of peace ending the Prayer) after each two Rak‘ahs. It is offered with long recitation, long Rukoo‘ (bowing), and Sujood (Prostration).During it a certain number of utterances of Tasbeeh (saying: “Subhaan Allaah [Glory be to Allaah]”), Tahmeed (saying: “Al-hamdu lillaah [All praise is due to Allaah]”) and Tahleel (saying: “Laa ilaahaa illaa Allaah [There is no god except Allaah]”) are recited; therefore, it is a long Salaah. Does this Salaah have a basis in Sharee‘ah (Islaamic law)? What is the ruling on it?
Answer: It has not been authentically reported that the Prophet (peace be upon him) prescribed the offering of a four-Rak‘ah Salaah (Prayer consisting of four units) during the nights of the six days of Shawwaal when Sawm (Fasting) is recommended as an act of Sunnah (supererogatory act of worship following the example of the Prophet), or during any of the nights of this month. This Salaah is a Bid‘ah (innovation in religion) and setting a fixed time to offer it is a Bid‘ah. Performing it in the manner mentioned is also a Bid‘ah... read more here.