as Zuhr, but he should not intend Zuhr until after the imam has said the salām. This view is correct, because Zuhr is subsidiary to Jumu‘ah. Thus, when he shifts from Jumu‘ah to Zuhr, he has shifted from the original obligation to its substitute, while both are the obligatory prayer of that time. In this issue, the well-known rule may constitute an exception: “Shifting from one specified prayer to another invalidates the first, and the second is not validly commenced by it.”

An example is a person who begins the prayer intending Zuhr, having forgotten, then remembers that it is the time of ‘Asr and that he had already prayed Zuhr. During the prayer, he changes his intention to ‘Asr.

We would say: His Zuhr has become invalid, because he invalidated it; and his ‘Asr has not validly commenced, because he did not intend it as ‘Asr from its beginning. A specified prayer must be intended from its outset. However, we say that this case may be excepted from the rule on the basis that Zuhr is the substitute for Jumu‘ah when it is missed, and is therefore subsidiary to it. He has not shifted to something wholly different in every respect.

An important issue that commonly arises for people during the Hajj and ‘Umrah seasons in the Sacred Mosque is the following:

When a person is crowded out of being able to prostrate. It says in al-Rawḍ: “Whoever begins the prayer with the imam and is then crowded out of prostrating must prostrate upon another person’s back or foot.”

For example, a person joins the imam for Jumu‘ah, but the people are tightly packed. When he wishes to prostrate, he finds no place in which to prostrate. We say: You must prostrate upon a person’s back or foot.

Some scholars said that if he is crowded out, he should wait until the people stand up,