Answered by Shaykh Faraz Rabbani
If one is in the middle of reciting Qur’an in their salaah and during the recitation they get forget the next proceeding ayah, what should they do? The question came up in a halaqa meeting, and I was interested in the Hanafi position.
Can they go back and re-recite the ayat to help remember and then keep going? Can they begin a new surah at that point? Or should they just stop their recitation and go into ruku? Should they make Sujood as-Sahw?
If you have recited the wajib amount of the Qur’an in that rakat, which is the equivalent of 3 short verses, then it is best to simply go into ruku at that point. However, if you go back and repeat the same verse in order to remember, then this is not wrong, and no forgetfulness prostration is needed. A prostration is not needed, too, if you begin a new surah in this situation, but it is not good to do so. However, it you have not recited the wajib amount of the Qur’an, then you may do either of these without blame.
IF you pause in your prayer, doing nothing of its actions, for the extent of three tasbihs [= saying “Subhan Allah”], then you have left a wajib and must do a forgetfulness prostration at the end of the prayer.