is counted for you. Must he perform the prostration for forgetfulness or not? It will come later, Allah willing, that the follower is not required to perform the prostration if he has not missed any part of the prayer. But if he has missed part of the prayer, he must perform it.
If he says, “It seems more likely to me that I did not catch it,” we say: Do not count this rakʿah; complete your prayer, then perform the prostration for forgetfulness after the salām. If he says, “I am uncertain, and it does not seem more likely to me that I caught it,” we say: Base your prayer on certainty; do not count it; complete your prayer; and perform the prostration for forgetfulness before the salām.
Issue: If one bases his prayer on certainty, or on what seems more likely to him, then it becomes clear that he was correct in what he did, must he perform the prostration for forgetfulness?
For example, a man is uncertain whether he has prayed three or four rakʿahs, with neither possibility outweighing the other. So he treats them as three and performs a fourth rakʿah; but during that rakʿah, he becomes certain that it is the fourth.
The scholars have two views regarding this:
The first view: (2) He is not required to perform the prostration, because it has become clear that there was neither an addition nor an omission. The prostration is only required to make up for what was omitted, whereas here he neither omitted nor added anything. The Prophet, peace and blessings be upon him, said: “and he does not know whether he has prayed three or four,” (3) whereas this man knows how many rakʿahs he prayed; therefore, no prostration is due from him.
The second view: He must perform the prostration, because the Messenger, peace and blessings be upon him, said: “and he does not know how many he has prayed.” This is so that he may base his prayer on what he has determined; and the apparent meaning is that, even if he comes to know afterward, he must still prostrate, due to his words: “If he has prayed five, they will make them even for him