the presumption is that he did not expect it. Thus, the hadith of Ibn Abbas remains decisive and free of any counterargument, and the obligatory prayer is analogized to the voluntary prayer by an analogy in which there is no room for doubt.

The third type of change in prayer is that mentioned by the author in his statement:

“And if a follower separates without an excuse, [his prayer] is invalid . . .”

“And if a follower separates without an excuse, [his prayer] is invalid.” This is termed changing from following an imam to praying separately. It requires further detail: if there is an excuse, it is permissible; if there is no excuse, it is not permissible.

For example, a follower enters the prayer with the imam, then finds reason to separate, so he separates and completes his prayer on his own. We say: if this is due to an excuse, it is valid; if it is without an excuse, it is invalid.

An example of a valid excuse is when the imam prolongs the prayer beyond what is prescribed by the sunnah. In that case, it is permissible for the follower to separate. The evidence is the account of the man who prayed with Mu'adh, who would pray the night prayer with the Prophet ﷺ and then return to his people and lead them in that same prayer. One night, he began the prayer by reciting a long surah, al-Baqarah. A man then separated and prayed by himself. When Mu'adh learned of this, he said, “He has become a hypocrite,” meaning because he had left the congregation of the Muslims. But the man complained of this to the Prophet ﷺ, and the Prophet ﷺ said to Mu'adh, “Do you wish to be one who puts people to trial, O Mu'adh?” (1) He did not rebuke the man. This proves that a follower may separate because the imam has prolonged the prayer—but on condition that the prolonging exceeds the sunnah, not merely what is customary.