Secondly, when the imam has taken his seat on the pulpit on Friday, Ibn Nāfiʿ and Ibn al-Qāsim relate from Mālik that originally there were only two calls to prayer, the third being added later. What is reprehensible, therefore, is selling after the second call—the one that follows the imam’s sitting on the pulpit. The jurists are unanimous that, if the sale is noticed in time, it must be annulled. They differ, however, when the moment has already passed.

• One view, reported by Ibn ʿAbdūs, is that no compensation is due, because the prohibition pertains solely to the time of the transaction.
• Another opinion holds that the buyer remains liable for the item’s value, just as in every other invalid sale.
• Ibn al-Qāsim maintains that the value is assessed at the moment the buyer took possession.
• Ashhab says it is assessed after the prayer.
• Ibn Ḥabīb prefers Ashhab’s view, comparing it to fruit sold before its soundness appears, for which liability attaches when its sale becomes lawful.

Among the invalid sales is a salam (forward-purchase) in a specific standing crop before it has been threshed, or in a specific fruit before it has begun to ripen. The contract stipulates that possession of the crop be taken after it has dried, and of the fruit after it has become wholesome. If delivery is delayed until after that stage, the buyer must turn the crop over to the owner once it has dried and pay its value as appraised on the day of cutting, not on the day of purchase. Similarly, should he take possession of the fruit while it is still fresh and no equivalent can be found, he must pay its value, while retaining the right to wages for his upkeep of the trees, cutting of the fruit, and harvesting of the crop.

It is likewise invalid to buy a specific commodity—animal or otherwise, everything except real estate—while setting a deferred deadline for taking delivery, unless the period is short, such as one, two, or three days. Another invalid contract is to purchase goods with dinars or dirhams whose weight is unknown, or with copper coins whose number is unknown.

Also invalid is the stipulation of immediate cash payment (naqd) in the sale of ʿuhda (liability sale), in a sale with an option (khiyār), in muwāḍaʿa (sale at a mutually agreed discount), or in the sale of an absentee item located more than three days away—except in the case of real estate, where immediate payment is permissible whether or not it is stipulated. The rulings for absentee sales of other kinds, for sales with an option, and for