As for the majority’s evidence for their view that the prayer of one standing alone behind the row is valid—namely, that he has done what he was commanded to do in following the imam—this is correct. However, there are other obligations besides following the imam, one of which is joining the row. Joining the row is obligatory; therefore, if he neglects this obligation, his prayer is invalid.

As for their evidence that Ibn Abbas stood alone when the Prophet, peace and blessings be upon him, took him by the head and positioned him on his right (1), this was only a momentary isolation. We do not hold that the prayer is invalid in such a case. Thus, if someone comes and says the takbir behind the row, knowing that one or two men behind him will join him, there is no harm in this, so long as he does not miss the rak‘ah; his prayer is valid. During this brief moment in which he stood alone, it cannot be said that he prayed alone behind the row or behind the imam. Thus, the argument based on the hadith of Ibn Abbas is weak.

As for their claim that the hadith, “There is no prayer for one who prays alone behind the row” (2), is a negation of completeness, this is refuted. For when negation occurs, it has three levels:

The first and second levels are that it denotes the negation of physical existence; if that is not possible, then it denotes the negation of legal existence—that is, the negation of validity. The hadith under discussion cannot be a negation of physical existence, since it is possible for a person to pray alone behind the row. It must therefore be a negation of validity, and validity is legal existence, since there is nothing to preclude understanding it as a negation of validity. These, then, are two levels.