Is performing loud recitation (Jahran) where silent recitation (Ikhfat) is prescribed, or vice versa, an invalidating action in prayer?
Chapter on the Two Prostrations of Forgetfulness
Al-Mughni
Book of Prayer
Primary text
Reciting loudly where silence is required, or silently where loudness is required, are both Sunnah acts related to the prayer. Omitting them intentionally does not invalidate the prayer. The ruling regarding prostration of forgetfulness (Sujud as-Sahw) for such an omission is subject to scholarly difference. The primary position holds that prostration is not prescribed for this omission, even if done out of forgetfulness. This view is held by Al-Hasan, 'Ata', Salim, Mujahid, Al-Qasim, Ash-Sha'bi, and Al-Hakim. Anas recited loudly during Dhuhr and Asr prayers and did not perform Sujud as-Sahw, which is also the position of 'Alqamah and Al-Aswad. This constitutes the Madhhab of Al-Awza'i and Ash-Shafi'i, based on the premise that since it is a Sunnah, its omission does not necessitate prostration.
Supporting text
A second opinion states that prostration is prescribed for such an omission, which is the Madhhab of Malik and Abu Hanifah concerning the Imam. The basis for this is the Prophet's statement, 'If any one of you forgets, he should perform two prostrations.' Furthermore, because it is an omission of a verbal Sunnah, prostration is prescribed for it, similar to omitting the Qunut or the first Tashahhud. Ahmad stated that if one performs it, there is no harm, but it is not obligatory ('ala), meaning it remains recommended (mustahabb) but not required (wajib).