However, the apparent wording of the hadith is general and unrestricted. Even though the buyer can no longer rescind the sale once the khiyār (option) period has lapsed, he may still try to contrive a pretext that would invalidate the contract, or at the very least he might regret the purchase, thinking the seller has cheated or taken advantage of him. Such feelings breed enmity and hatred, and this is especially true when only a short time has passed. If, on the other hand, a long interval has elapsed, there is no objection, for the longer the gap the harder—indeed nearly impossible—it becomes to revoke the contract.

In sum, we face three situations:

1. Buying or selling against one’s brother while the khiyār period is still in effect: this is unquestionably forbidden.
2. Doing so shortly after the option has expired: the scholars differ, but the correct view is that it remains forbidden.
3. Doing so after a considerable lapse of time—such as a month, two months, or more: there is no harm in this, for people trade goods among themselves in this and other ways.

A similar example is leasing over another’s lease. Suppose someone approaches a tenant who has rented a house for a year at one thousand riyals and says, “I can get you a better place for eight hundred.” This is forbidden, for it is an act of aggression like buying over his sale.

Likewise is bidding over another’s bid, a matter explicitly stated in the narration recorded by Muslim. Bidding over someone’s bid means that when a person has offered a price for a commodity and the seller has inclined toward it,