This order is a condition for the prayer; if one neglects it, his prayer is not valid, based on the evidence we have mentioned from the hadith of Abu Jum'ah and the hadith of Ibn Umar. It is also because it is an order that is obligatory in the prayer, so it is a condition for its validity (15), [like the order in] (16) the two combined prayers, and the bowing and prostration. Once this is established, we return to the issue of the Book, which is when one enters into the current prayer (al-hadirah), then recalls during it that he has a missed (fa'itah) prayer, and the time is ample. He shall complete it, perform the missed prayer, then repeat the prayer he was in, whether he is an imam, a follower (ma'mum), or praying alone (munfarid). This is the apparent view of al-Khiraqi and Abu Bakr, and it is the view of Ibn Umar, Malik, al-Layth, and Ishaq regarding the follower. It is what the group narrated from Ahmad regarding the follower, and a group narrated from him regarding the one praying alone that he breaks the prayer and performs the missed one. It is the view of al-Nakha'i, al-Zuhri, Rabi'ah, and Yahya al-Ansari regarding the one praying alone [and no one else] (17), (18). It was narrated from Ahmad regarding the one praying alone that he completes the prayer, and regarding the follower that he breaks the prayer. Harb narrated regarding the imam that he leaves, and the followers restart. Thus, there are two narrations concerning all: one is that he breaks it and performs the missed prayer; the other is that he completes it, performs the missed prayer, and then repeats the one he was in. Tawus, al-Hasan, al-Shafi'i, and Abu Thawr said: He completes his prayer and performs the missed prayer, and nothing else.
(15) Omitted from: The Original. (16) In MS (m): "like the order". (17) In MS (m): "and others". (18) From here to the end of his saying: "and he repeats them both together", it appears in MS (m): "Harb narrated from Ahmad, regarding the imam: he leaves, and the followers restart. Abu Bakr said: No one narrates this except Harb, and it has been narrated from him regarding the follower that he breaks [the prayer], and regarding the one praying alone, that he completes the prayer. Similarly, the ruling for the imam must be the same, so there are two narrations for performing it in all cases; one of them is that he completes it. Tawus, al-Hasan, al-Shafi'i, and Abu Thawr said: He completes his prayer and performs the missed prayer, and nothing else. Our argument for the obligation of repetition is the hadith of Ibn Umar, the hadith of Abu Jum'ah, and because it is an obligatory order, its requirement became a condition for the validity of the prayer, like the order of the two combined prayers. Our argument for the fact that he completes the prayer is the Almighty's saying: {Do not invalidate your deeds}. And the hadith of Ibn Umar, and the hadith of Abu Jum'ah as well. He said: It is determined that it should be interpreted as him recalling it while he is in the prayer, for if he had forgotten it until he finished the prayer, its performance would not be obligatory. And because it is a prayer in which a missed prayer was recalled, it is not corrupted, just as if he were a follower, for the apparent view of the school (madhhab) is that he proceeds with it. Abu Bakr said: Ahmad's statement does not differ regarding [the case where] he is behind the imam; that he proceeds with the imam and repeats them both together."
