What does one do if he forgets a sunnah (recommended practice) of the prayer?
Machine translationRead the Arabic original
Question:
May Allah reward you, Honorable Shaykh. This questioner says: If a person praying forgets a sunnah (recommended practice) of the prayer, such as raising his voice in the third rak'ah (unit of prayer) or something else, is it obligatory for him to perform sujud al-sahw (the prostration for forgetfulness)? Or is it recommended? Or what does he do?
Answer:
It is recommended to perform sujud al-sahw (the prostration for forgetfulness) if one leaves a sunnah (recommended practice), or raises his voice where he should lower it, or lowers his voice where he should raise it. In this case, sujud al-sahw is not obligatory for him, but if he performs it out of recommendation, there is no harm.
May Allah reward you, Honorable Shaykh. This questioner says: If a person praying forgets a sunnah (recommended practice) of the prayer, such as raising his voice in the third rak'ah (unit of prayer) or something else, is it obligatory for him to perform sujud al-sahw (the prostration for forgetfulness)? Or is it recommended? Or what does he do?
Answer:
It is recommended to perform sujud al-sahw (the prostration for forgetfulness) if one leaves a sunnah (recommended practice), or raises his voice where he should lower it, or lowers his voice where he should raise it. In this case, sujud al-sahw is not obligatory for him, but if he performs it out of recommendation, there is no harm.
Source
قناة «العلامة الدكتور صالح الفوزان»، ماذا يفعل من نسي سنة من سنن الصلاة؟ لمعالي الشيخ صالح الفوزان — youtube.com
The Arabic text is a machine transcription of the audio recording.