prostrating. As for bowing, magnify the Lord therein; and as for prostration, increase your supplication therein, for it is more worthy that you will be answered.” (1)
“And if he recites the tashahhud while standing, or recites a surah in the final two rak‘ahs, his prayer is not invalidated, nor is the prostration of forgetfulness required of him; rather, it is prescribed …”
His statement, “recites the tashahhud while standing”: the tashahhud is prescribed while sitting. But if he forgets and recites the tashahhud while standing, he has uttered something prescribed in the prayer, but in a place other than its proper place.
His statement, “or recites a surah in the final two rak‘ahs”: this too is something prescribed, but in a place other than its proper place, because in the final two rak‘ahs it is not prescribed to recite anything besides al-Fātiḥah, according to the well-known position of the madhhab. (2) We have mentioned in the chapter on the description of the prayer that one should occasionally recite something additional in the final two rak‘ahs. (3)
Note: His statement, “such as recitation while prostrating,” means when one also says, “Glory be to my Lord, the Most High,” because if he recites while prostrating but does not say, “Glory be to my Lord, the Most High,” then he has omitted an obligatory act and must perform the prostration of forgetfulness. However, if he utters something prescribed in the prayer in a place other than its proper place, while also performing the prescribed utterance for that particular place—such as reciting while bowing along with saying, “Glory be to my Lord, the Magnificent”; or reciting while prostrating along with saying, “Glory be to my Lord, the Most High”; or reciting while sitting between the two prostrations along with saying, “My Lord, forgive me”; or reciting during the tashahhud while also reciting the tashahhud—
His statement, “his prayer is not invalidated”: its apparent meaning is that this applies even if he recites while bowing or while prostrating, because recitation is, in general, something prescribed in the prayer, though not in this particular place.