An example concerning a specified period: One says, “I lease you this house for one year for one hundred riyals, with the term beginning from the conclusion of the contract.” The other says, “That is fine, but I have the option for ten days.” This condition is not valid.

Another example: One says, “I lease you this house for one year for one hundred riyals, on the condition that the term begins on the first day of Rajab, and that the option between us remains until the twenty-fifth of Jumada al-Thani. We are now on the twelfth night.” This is permissible, because the lease term begins after the stipulated option period has ended, and there is no harm in it.

But why is a stipulated option not valid in a lease whose term begins from the conclusion of the contract?

The reasoning is that this results in one of two things: either the benefits are left unused, or they are taken during the option period, and neither is permissible.

Now, if I were to say, “I lease you my house for one year for ten thousand, on condition that I have the option for one month,” then during that month we do not know whether the benefit belongs to the owner of the house or to the tenant. If the lease remains in force, it belongs to the tenant; but if the lease is rescinded, it belongs to the owner of the house. Thus, during the period in which the option exists, it is unknown to whom it belongs. The matter is therefore undecided as to whether the benefit during the option period belongs to the lessor or the tenant. This leads to gharar (excessive uncertainty), and whatever entails gharar is void.

This reasoning is defective. The correct view is that it is permissible to stipulate an option, even for a period that immediately follows the contract, and even if the option does not expire until after the beginning of a lease term that does not immediately follow the contract.