Is the prostration of forgetfulness (sujūd as-sahw) obligatory for one who mispronounces (laḥn) in Al-Fātiḥah or what follows it, and is it for an addition or omission, and before or after the salām, and what are the implications of a mispronunciation that does not alter the meaning?

According to the Hanbalis, the prostration of forgetfulness (sujud al-sahw) is obligatory for one who makes a grammatical error (laḥn) in recitation that changes the meaning, whether in Al-Fatihah or other surahs, including the omission of a letter from Al-Fatihah. However, a grammatical error that does not change the meaning does not necessitate the prostration of forgetfulness. Some Hanbalis, including Al-Majd Ibn Taymiyyah, hold that one who makes a grammatical error due to forgetfulness or ignorance is not required to perform the prostration of forgetfulness, even if their error changes the meaning. The adopted position of the madhhab, however, is that the prostration of forgetfulness is obligatory for such an error, even if it was due to forgetfulness or ignorance. The preferred time for the prostration of forgetfulness is before the taslim (salutation of peace), but it is permissible if performed after it.