Now, we have said: “Neither a sale nor a purchase is valid.” Might someone not say: Are sale and purchase not inseparable?
We reply: What he means here by “purchase” is acceptance. A seller may initiate the sale by saying, “I have sold you this for ten,” and then the caller to prayer says, “Allah is the Greatest,” after which the other party says, “I accept.” Thus, what took place after the call was the purchase—that is, the acceptance. Otherwise, it is well known that there is no sale without a purchase and no purchase without a sale. Yet acceptance may occur after the call, while the offer occurred before it; in that case, we say that the sale is invalid.
His statement, “by one upon whom the Friday prayer is obligatory,” includes both one upon whom it is obligatory in his own right and one upon whom it becomes obligatory by virtue of another factor. The former is one in whom the conditions of obligation are fulfilled. As for the latter, he is one in whom those conditions are not fulfilled, but once the Friday prayer is established, it becomes obligatory for him. An example is the traveller who is required to complete his prayers—according to the madhhab, this is one who intends to reside for more than four days. Explaining this in detail would require us to return to the conditions of those upon whom the Friday prayer is obligatory; these are mentioned in the chapter on the Friday prayer.
His statement, “after its second call,” informs us that Friday has two calls: a first and a second. The second is the one that existed in the time of the Prophet ﷺ: when the imam arrived, the caller to prayer would make the call. The verse is therefore understood in reference to it, since it was revealed at a time when only one call existed, namely the second call. Hence, we say that the ruling is attached to it. As for the first call, it was introduced during the caliphate of the Commander of the Believers, Uthman ibn Affan—may Allah be pleased with him—when Madinah had expanded and people lived at a distance. He instituted two calls for Friday so that