It is not valid. This (43) is the position of al-Thawri, Ishaq (44), and the scholars of opinion (ashab al-ra'y), in both obligatory and supererogatory prayers alike, because he did not intend the imamate at the beginning of the prayer, so it is not valid, just as if one followed a follower. It was narrated from Ahmad that he said: "I have some reservations about it," even though the hadith of Ibn 'Abbas supports it. This is the school of al-Shafi'i, and it is the correct view, if Allah the Almighty wills, because it has been established in supererogatory prayer by the hadith of Ibn 'Abbas, and the hadith of 'Aishah: "The Messenger of Allah (peace and blessings of Allah be upon him) used to pray at night, and the wall of the chamber was low, so people saw the figure of the Messenger of Allah (peace and blessings of Allah be upon him), and some people stood to pray as he prayed." We have already mentioned this (45). The principle is the parity of obligatory and supererogatory prayer regarding intention, and this is strengthened by the hadith of Jabir and Jabbar regarding obligatory prayer. Furthermore, necessity calls for shifting the intention to imamate, so it is valid (46), as in the case of substitution (istikhlaf). The clarification of the necessity is that if a group of people arrives while a person is praying alone and they join behind him, if he were to break his prayer and inform them (47) of his status, it would be reprehensible, and he would be committing an act prohibited by His saying (the Almighty): "And do not invalidate your deeds" (48). If he completes the prayer with them and then informs them of the invalidity of their prayer, it would be even more reprehensible and burdensome. Moreover, being alone is one of the two states of non-imamate in prayer, so transitioning from it to imamate is permissible, just as if he were a follower; their analogy is invalidated by the state of substitution.

Section: If he begins prayer alone, then intends to make himself a follower by being present with a congregation, intending to enter with them in their prayer, there are two narrations. The first is that it is permissible, whether he is at the beginning of the prayer or has already prayed one rak'ah or more, because he has shifted himself into a congregation, so it is permitted, just as if he had intended the imamate. The second is that it is not permitted, because he has shifted himself to become a follower without