What is the ruling on the landlord retracting his promise to waive the rent for the shop during the coronavirus pandemic which caused its closure, and am I obligated to pay the rent or not?

The basic principle in a lease contract is its binding nature. However, it is permissible to terminate it due to a sudden impediment, such as the Coronavirus pandemic, which led to the closure of shops. This is the view held by the Hanafis, Malikis, Ibn Taymiyyah, and Ibn Uthaymeen.

If the contract was not terminated and the owner promised to waive the rent during the pandemic, there are two scenarios: 1. If retracting the promise is after the period has passed: It is impermissible for him to do so, because he has gone back on waiving a debt that had become settled, and what has been waived does not return. This is similar to retracting a gift after it has been taken possession of, which is forbidden according to the Prophet's ﷺ saying: "The one who retracts his gift is like a dog that vomits and then returns to its vomit." 2. If retracting the promise is before the period has passed: It is permissible for him to do so according to the majority of scholars, and it is like retracting a gift before it has been taken possession of. However, it involves deceiving the tenant.

Accordingly, it is not permissible for the owner to demand rent for the period he waived, but he may demand rent for the period thereafter.