When he spoke in terms encompassing both cases, he said:

“If he adds or omits something, let him perform two prostrations.”

He also said:

“If any of you does not know how much he has prayed, let him perform two prostrations while seated.”

Thus, when he mentioned omissions, additions and doubt in general terms, he commanded two prostrations without stipulating that they be performed before the closing salutation. When he commanded the worshipper to exercise his best judgment, he commanded the two prostrations after the closing salutation. These, then, are his commands, may Allah bless him and grant him peace, concerning these matters; do not depart from them.

“It is not for a believing man or a believing woman, when Allah and His Messenger have decided a matter, to have any choice in their affair.”

However, someone who always performs the prostrations before the closing salutation, or always performs them afterwards, acting on an interpretation, incurs no blame. If the Sunnah subsequently becomes clear to him, he should henceforth act according to what has become clear to him, without having to repeat his prayers.

Likewise, anyone who omits an obligation because he did not know it was obligatory must fulfil it once he learns of its obligation, but need not repeat what he has already performed, according to the more correct of the two views within Ahmad’s school and elsewhere. The same applies to someone who does something prohibited in prayer without knowing that it is prohibited, then learns of the prohibition—for example, someone who used to pray in camel resting places, or who did not perform an obligatory ablution because he did not know it was obligatory, such as ablution after eating camel meat.

This differs from the case of someone who forgets: a person who knows of the obligation but forgets must pray when he remembers, as the Prophet, may Allah bless him and grant him peace, said:

“Whoever sleeps through a prayer or forgets it, let him pray it when he remembers it.”

As for someone who did not know of the obligation, once he learns of it, he must perform the prayer whose time is then due and the prayers thereafter, but need not repeat his earlier prayers. As is established in the two Sahīh collections, the Prophet, may Allah bless him and grant him peace, said to the Bedouin