The prayers which should be performed in sequence
763. One should always offer ‘Asr prayers after the Zuhr prayers, and the ‘Isha prayers after the Maghrib prayers. If one intentionally offers ‘Asr prayers before Zuhr prayers, or ‘Isha prayers before Maghrib prayers, one's prayers would be void.
764. If a person starts Namaz with the Niyyat of Zuhr prayers, and during the prayers he recollects that he has already offered Zuhr prayers, he is not allowed to change the Niyyat to the ‘Asr prayers. He should abandon that Namaz, and start ‘Asr Namaz. And the same rule applies to the Maghrib and the ‘Isha Namaz.
765. If a person somehow becomes sure while offering the ‘Asr prayers that he has not offered the Zuhr prayers, and changes Niyyat to the Zuhr prayers, but later he recollects that he has in fact already offered the Zuhr prayers, as per obligatory precaution, he can again revert to ‘Asr, and complete the prayers, and if he has performed any Rukn (like Ruku' or Sajdah) or part of it with the Niyyat of Zuhr, then after completing his prayers he will have to offer ‘Asr prayer all over again.
766. If, while offering the ‘Asr prayers, a man doubts whether he has offered the Zuhr prayers or not, in such case he should change his Niyyat to Zuhr. However, if the time is so short, that that the Maghrib time will set in by the time he finishes, then he should consider that he has offered his Zuhr prayers and should finish his prayers with the Niyyat of ‘Asr.
767. If, while offering the ‘Isha prayers, and before the Ruku’ of 4th Rak’at, a man doubts whether he has offered Maghrib prayers, if the time is so short that by the time he finishes it will be mid night, then he should complete the Namaz with the same Niyyat of ‘Isha, then later on he should offer Maghrib with the intention of complying with the order or Almighty Allah. But if he has enough time that even one Rak’at will be in the common time of offering, then he should change his Niyyat to Maghrib prayers, and should finish his Namaz in 3rd Rak’at. And thereafter he should offer his ‘Isha prayers.
768. If while offering ‘Isha prayers, a person doubts after reaching the Ruku’ of the 4th Rak’at, whether he has offered Maghrib prayers, he should complete the ‘Isha Prayers. Then, he should pray Maghrib, as per obligatory precaution, thereafter he should offer his ‘Isha prayers all over again. However, if this doubt occurs during the specific time of ‘Isha, then it is not necessary to offer Maghrib prayers.
769. If a person is praying a particular Namaz again as a precaution, and during the prayers he recollects that he has not offered the preceding Namaz, he cannot change Niyyat to that prayers. For example, when offering the ‘Asr prayers again as a measure of precaution, he recollects that he has not offered the Zuhr prayers, he cannot change Niyyat to Zuhr prayers.
770. It is not permissible to change Niyyat from Qadha to Ada (i.e. prayers which is offered within the prescribed time), nor from Mustahab to obligatory prayers.
771. If a person has sufficient time at his disposal to offer prayers within the time, he can, while offering the prayers, change Niyyat to Qadha prayers, provided that it is possible to do so. For example, if he is offering Zuhr prayers, he can change to
Qadha of dawn prayers, only when he has not entered the Ruku’ of the third Rak’at. However, if a person begins his prayer with the Niyyat of Ada and before beginning his prayer he had the intention of changing his Niyyat during the prayer, validity of such prayers are objectionable, and it is better to avoid such things.