Is a lease valid if the rent for the first month is specified and subsequent rent is calculated proportionally?
General Chapter
Al-Mughni
Book of Leasing
Primary text
If a lessor states, 'I leased it to you for one month for one dirham, and whatever is more shall be calculated accordingly,' the contract is valid only for the first month because it was specified uniquely in the contract. The rest of the contract is void because the subsequent rent is indeterminate (majhul).
Supporting text
It is probable that the contract is valid for every month the tenant occupies the property, similar to stating, 'I leased it to you for one dirham every month,' as the meaning of both statements is essentially the same.