Reciting Surah Faatiha Loudly in the Closing Rakaahs of the Maghrib or Isha salaahs

Q: Salaah-633: Respected Mufti Sahib. You had stated in a previous Fatwa that Sajdah Sahw will become Waajib (compulsory) if an Imaam recites the Qiraa'ah aloud in the closing Rakaahs of a Fardh salaah. You also favoured us by quoting extracts from Bahrur Raa'iq and Tahtaawi. What I wish to know is that why should Sajdah Sahw become necessary when it is Sunnah to recite Qiraa'ah in these closing Rakaahs of the Fardh salaah?

Answer: According to the preferred opinion, it is Sunnah to recite Surah Faatiha in the closing Rakaahs of the Fardh salaah, but according to consensus, it is Waajib (compulsory) to recite it silently. Therefore, if an Imaam recites it audibly, he will be guilty of leaving out a Waajib (compulsory) act and Sajdah Saw will be necessary. And Allaah knows best what is most correct.

Fatawa Rahimiyyah vol.2