• Ahmad was also asked about a man who leaves two prostrations from the Dhuhr prayer, one prostration from each rak'ah. He said: "He does not count these two rak'ahs. If he remembers them during his prayer before he performs the taslim, he must repeat two rak'ahs."

• I said to Ahmad: "What if he forgets a prostration from his prayer and remembers it after he has performed the taslim and spoken?" He said: "He must repeat the prayer." I asked: "And is it the same if he forgets the Opening of the Book (Fatihah) in a rak'ah?" He said: "Yes."

• I asked Ishaq ibn Ibrahim, saying: "A man forgets a prostration from his prayer?" He said: "If he does not know from which rak'ah he forgot it, he should perform a prostration for the first, then repeat what follows it from the rak'ahs, because it is not valid for him to have a mandatory act remaining upon him while he is praying after it. But if he knows from which rak'ah it is, he should perform this prostration and repeat what follows it."

• I asked Ishaq on another occasion, saying: "A man forgets a prostration from a rak'ah?" He said: "If he knows from which rak'ah he forgot it, he should perform one prostration in order to complete by it the rak'ah from which he forgot the prostration, then look at what was after his forgetfulness of the prostration and repeat it."

• I said to Ahmad: "What if he does not know from which rak'ah he forgot it?" He said: "He must repeat the entire prayer." Then he said: "He should attribute it to the beginning of every rak'ah, so he repeats one prostration and then prays three rak'ahs." And he adopted this view.