So this report and the report of ‘Ammar, in which he said, "He does not repeat even if he reaches China," can be interpreted as applying to a case where the person does not remember with certain knowledge, but rather recalls it with suspicion and is overcome by doubt. In such a case, he may add the remaining part of the prayer as a precaution, not as an obligation. For we have already clarified that once a person has finished and exited the state of prayer, no attention is given to any subsequent doubt. It is also possible that the report refers to having omitted two rak‘ahs of a supererogatory prayer, and it does not specify that they were from an obligatory prayer. What further clarifies what we have presented is:
Commentary #3