The same applies to one who is afraid: the Friday Prayer is waived for him, but if he attends it, it becomes obligatory upon him, is established through him, and he may validly serve as its imam.
If someone were to ask: What is the difference between him and the traveller or the slave?
The answer is that the traveller and the slave lack a condition that makes the obligation binding, and thus are not among those for whom it is binding. As for one from whom it has been waived due to an excuse, he has a factor preventing the obligation from applying to him, yet he is among those for whom it is binding. Once he comes to the place where it is held, the preventing factor ceases, and he becomes like one in whom no such factor is present.
“Whoever, among those required to attend the Friday Prayer, performs the Zuhr Prayer before the imam’s prayer, his prayer is not valid. ……”
His statement, “Whoever, among those required to attend the Friday Prayer, performs the Zuhr Prayer before the imam’s prayer, his prayer is not valid,” means that if someone who is required to attend performs the Zuhr Prayer, his prayer is invalid. Consider the author’s wording: “among those required to attend the Friday Prayer”; he did not say, “among those upon whom the Friday Prayer is obligatory.” This is so that his words may encompass both one for whom it is obligatory in his own right and one for whom it becomes obligatory due to others. For the jurists divide people into two categories:
The first is one who is required to attend the Friday Prayer due to others. The Friday Prayer is not established through him, nor may he validly serve as its imam.
The second is one who is required to attend it in his own right. He may validly serve as its imam, and it is established through him.
An example is a traveller who arrives in a town where the Friday Prayer is held, and the call to the Friday Prayer is made. He is then required to attend, though it is not obligatory upon him in his own right, but due to others. If this traveller performs the Zuhr Prayer before the imam’s prayer, his prayer is invalid, because he has done what he was not commanded to do and neglected what he was commanded to do. Thus, he has performed a deed that is not in accordance with the command of Allah and His Messenger, for he was commanded to attend the Friday Prayer and perform it, yet he performed Zuhr instead. It is therefore not accepted from him, due to the Prophet’s saying: “Whoever performs a deed that is not in accordance with this matter of ours will have it rejected.” That is, it is rejected from him. Moreover, his performance of the Zuhr Prayer while attendance is obligatory upon him is like unlawfully appropriating the time, because this time is fundamentally designated for the Friday Prayer.
Another example:
A man residing in the town is at home with his companions. When the time for Zuhr comes, they perform the Zuhr Prayer before the Friday Prayer; their prayer is invalid.
A third example: