Rifāʿah ibn Rāfiʿ—which holds him accountable only for what he omitted (1) of those acts, and solely because he omitted it (2), while crediting him with what he performed, so that he is not like one who did not pray at all.

The response is:

This is also what we maintain (3): whoever performs the prayer but omits some of its obligatory acts is not in the same position as one who performs none of it. Rather, he is rewarded for what he performed and punished for what he omitted. He is instructed to repeat the prayer only to avert the punishment incurred by his omission, for omitting an obligatory act is a cause of punishment. Thus (4), if he is liable to punishment for omitting part of it, he must perform the prayer. If the omitted act has a prescribed compensation or can be performed on its own, he does so; otherwise, he performs it together with the other acts, since it cannot be performed separately.

If it is objected:

If (5) performing it alone was not an act of obedience, then he would not have been rewarded for it in the first place.

The response is:

When he initially performed it, he either did not know that doing so was impermissible or had forgotten—like someone who prays without ablution or forgetfully omits the obligatory recitation or prostration. He is therefore rewarded for what he performed and is not punished for his forgetfulness or mistake. He is nevertheless instructed to repeat the prayer because he did not initially perform what he had been commanded to do. This is like one who is asleep and awakens while the prayer’s time remains: he is instructed to pray because it is obligatory upon him within its prescribed time, if possible; otherwise, he performs it whenever (* he awakens, for it is then that he is instructed to perform it. As for when he is instructed to repeat it, it is understood that performing it *) (6) alone (7) is impermissible, and so he is not instructed to perform it alone (8).