The second case is where the follower separates from the imam due to an excuse. The imam then transitions from leading the prayer to praying alone: the follower may have a legal or physical excuse and so separates from his imam, leaving the imam by himself. Thus, he has transitioned from leading the prayer to praying alone.

The fifth type is the transition from leading the prayer to following an imam. The author mentioned it in his statement: “If the regular imam commences the prayer with those whom his deputy had led, and the deputy returns to following him, it is valid.” The regular imam is the appointed imam.

The situation mentioned by the author is that a man begins leading a group in prayer as the deputy of the regular imam, who had been absent. Then the regular imam arrives and steps forward to complete the congregational prayer with the people. His deputy steps back, if he finds a place in the row; otherwise, he remains on the imam’s right. In this case, the deputy imam transitions from leading the prayer to following an imam, and this is permissible.

The evidence for this is what occurred with the Messenger of Allah, may Allah’s blessings and peace be upon him, when he instructed Abu Bakr to lead the people in prayer. The Prophet, may Allah’s blessings and peace be upon him, then felt somewhat better, so he came out to the people and prayed with them. He sat on Abu Bakr’s left, while Abu Bakr was on his right. The Prophet, may Allah’s blessings and peace be upon him, pronounced the takbir, but his voice was faint; so Abu Bakr would pronounce the takbir after his takbir, so that the people could hear. (1) Thus, Abu Bakr transitioned from leading the prayer to following an imam, while the followers transitioned from one imam to another, yet they remained followers.