What is the ruling on partnership in a restaurant that sells shisha and leases part of its premises to a shisha vendor, what is the ruling on the profits generated therefrom, and is it permissible for a Muslim to continue in this partnership?

It is not permissible to lease a part of the shop for selling shisha, because it is forbidden, and because cooperation in sin is forbidden. It is also not permissible to use it as a means to attract customers. As for the profits of the halal (definition) restaurant, they are not affected by the presence of shisha if it is separate. However, the rent paid by the shisha vendor (such as the electricity bill) is not permissible because it is in return for a forbidden benefit, and one must dispose of it by spending it on Muslim welfare or giving it to the poor. The partner must be prevented from leasing a part of the shop for shisha, as he is not allowed to dispose of common property without the permission of his partner. And even if partnership with someone who does not care about what is forbidden is permissible in halal matters, it is better not to partner with him.