If by mistake I add another Surah after Surat al Fatiha in the third or fourth Rakats of a Fard prayer, will it be necessary for me to make Sajda Sahw at the end?
According to the Hanafi School of Islamic law, it is not impermissible or prohibitively disliked (makruh tahrim) to add another Surah after reciting Surat al-Fatiha in the third or fourth Rak’at of a obligatory (fard) prayer; rather, it is somewhat disliked (makruh tanzih) and ‘better’ to avoid, since the Sunna is to suffice with Surat al-Fatiha.
Sayyiduna Abu Qatada (Allah be pleased with him) relates that the Messenger of Allah (Allah bless him & give him peace) would recite in the first two Rak’ats the Umm al-Kitab [i.e. Surat al-Fatiha] and two Suras, and in the last two the Umm al-Kitab [on its own]…” (Sahih al-Bukhari, no 743)
As such, it is better to simply recite Surat al-Fatiha in the third and fourth Rak’ats of Fard prayers. However, if one – intentionally or unintentionally – adds another Surah, it does not necessitate a prostration of forgetfulness (Sujud al-Sahw).
It is stated in Al-Fatawa al-Hindiyya, a well known Hanafi Fiqh reference work, “If one recites in the last two Rak’ats [of a four unit Fard prayer] Surat al-Fatiha and another Surah, a Sujud of forgetfulness (sahw) will not be necessary. This is the more correct position.” (Al-Fatawa al-Hindiyya 1/126)
Imam Ibn Abidin, the renowned classical Hanafi jurist explains in his Radd al-Muhtar that although there are narrations from some Hanafi Imams that a Sujud al-Sahw is necessary for adding a Surah in the last two Rak’ats, the chosen and more correct opinion within the School is that it is not necessary. This is due to the fact that it is permitted to add another Surah in these Rak’ats, although better to avoid. (Radd al-Muhtar ala al-Durr al-Mukhtar 1/459, See also: Fatawa Mahmudiyya /7412 and Ahsan al-Fatawa 4/50)
And Allah knows best
[Mufti] Muhammad ibn Adam
Leicester , UK